THE OFFICE OF THE PRESIDENT, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT.

SECONDARY EXAMINATION SERIES

MARCH 2025

PHYSICS FORM FOUR

TIME: 2:30HRS

Instructions

1. This paper consist of sections A, B and C with total of eleven (11) questions

2. Answer all questions in sections A and B and two (2) questions from section C.

3. Section A carries sixteen (16) marks, section B fifty four (54) marks and section C carries thirty (30) marks

4. Non-Programmable calculators and mathematical table may be used.

5. Cellular phones and any unauthorized materials are not allowed in the examination room.

6. Where necessary the following constants may be used:

1.    Acceleration due to gravity, g = 10 m/s ²
2.   Density of water = 1.0 g/cm ³
3.    Linear expansivity of brass = 19 × 10 ⁻⁶°C ⁻¹
4.   Linear expansivity of iron = 10 × 10 ⁻⁶°C ⁻¹
5.    Specific heat capacity of aluminium = 900 J/kg°C

SECTION A (16 Marks) 

Answer all question in this section

1. For each of the items (i –x) choose the most from the given alternatives and write its letter beside the item number in the answer sheet (booklet) provided.

i)  Heat would be lost in the thermos flask if the walls of the glass container were not coated with silver. Which process contributes to this kind of heat loss?

1.   Radiation
2.   Conduction
3.   Convection
4.  Absorption
5.    Transmission

ii. In a light experiment, observing an object through a certain material showed that less light was transmitted and the image was distorted. Which type of material was used

1.   A translucent material
2.   An opaque material
3.   A luminous material
4.  A transparent material
5.    A non-luminous material

iii. Why oil is used as lubricant

1.   It has low density
2.   It is highly viscous
3.   It is flammable
4.  It is less viscous
5.    It is costle

iv. When silicon element is doped with phosphorus atom, it produces:

1.   P-type semiconductor
2.   Force
3.   intrinsic semiconductor
4.  bipolar semiconductor
5.    n-type semiconductor

v. A body is said to be in equilibrium if

1.   It moves with uniform speed
2.   The net force acting on it is zero
3.   The upward and downward forces are equal
4.  Its center of gravity is low positioned
5.    Its center of gravity is high

(vi) A bus carrying heavy load on its top carrier is likely to overturn because;

1.   It runs faster 
2.   Its center of gravity is low 
3.   Its center of gravity is high
4.  Its equilibrium is neutral 
5.    It is at stable equilibrium

(vii) The extremely narrow bore on the liquid-in-glass thermometer in which the thermometric liquid flows during expansion or contraction is known as;-

1.   Capillary tube 
2.   Steel index 
3.   Stem 
4.  Constriction 
5.    Bore

(viii) Which of the following conditions must be satisfied for a body to float?

1.   Apparent weight is equal to the difference between real weight of the body and itsupthrust
2.   Upthrust equal to the weight of the fluid displaced
3.   Real weight of the body equals to its upthrust
4.  Apparent weight is equal to the product of real weight of the body and its upthrust
5.    Density of a body is equal to the density of surrounding fluid

ix. Form four students were discussing on the properties of matter, where one of them said that solid has definite shape and all members of the group agreed. Which one could be the reason behind for solid to have definite shape?

1.   It has high adhesive force 
2.   It has high surface tension
3.   It has low viscosity 
4.  It has high cohesive force
5.    It has low adhesive force

x. ANGINJA was in the car, she tried to look at her friends who were outside of the car through a glass window, but she did not see them well. You as a form four student, what conclusion could you make on that glass window?

1.   It is transparent material 
2.   It is translucent
3.   It is opaque 
4.  It is not cleaned
5.    It is black

2.    Match the colours from List B which absorbed by the colour in List A by writing the letter of the correct response beside the corresponding item number in the answer booklet provided. (06 Marks)

SECTION B. 70 MARKS. ANSWER ALL QUESTIONS

3. (a)(i) What do you understand by the term specific heat capacity and specific latent heat of vaporization

(ii) Explain the factors that affect boiling point of water.

(b) What is the index of refraction for a certain medium if the light in air enters the medium at an angle of 30° and refracted at 22°C?

4. (a)Describe how a lens camera operates the same way as human eye. Give three points

(b) Briefly explain how conduction of heat can be applied in your daily life (Three reasons)

5. (a)Briefly explain why the doors of oven are made loosely fitting

(b) A steel bridge over a motor way is 20m at 0°C. How much longer is it at 20°C?

6. a) State the relationship between pressure, force and area.

b) Explain why one feels not comfortable when he/she lift a bucket of water by its handle made of thin metal. What will be the pressure experienced if the handle is made of thicker metal?

c) The mss of the cube is 120kg, if it measures 50cm x30cm x20cm, what is maximum pressure that it can exert?

7. a) A positively charged rod is brought near body A and B if body A is at a distance of 1cm and body B is a distance of 3cm, which of the two bodies will be attracted more?

b) i) What happens when two positively charged bodies brought into contact?

ii) Explain why a pieces of paper attracted by a plastic charged pen after few seconds fell off?

8. (a) Describe how a lens camera operates the same as human eye. Give three points (06 marks)

(b) Briefly explain how conduction of heat can be applied in your daily life (three reasons) (04 marks)

9. Weather forecasting shows that there is the possibility of occurring earthquake in Mtakuja village. The villagers are not aware with such disaster. As physicist, make villagers aware with

1.    Meaning of earthquakes ( 02 marks)
2.   The four key indicators observed before an earthquake occurs (04 marks)
3.    Suggest four precautions to be taken by villagers during an earthquake in order to minimize injuries and deaths. (04 marks

10. (a) Rutherford proton-neutron model shows that there are no electrons in the nucleus of an atom. How is it possible for a radioactive element to emit beta particles (electrons) from its nucleus? (04 Marks)

(b) Two identical free running trolleys are on a smooth horizontal runway. One trolley is at rest and the other approaches it at constant speed of 20 m/s.

(i) Using the principle of conservation of momentum, find the common speed of two Trolleys after the collision.

(ii) Why the kinetic energies before and after the collision are different? (05 Marks)

SECTION C. 15 MARKS

11. (a) Briefly explain why a piano can be distinguished from a violin even when they are playing notes of the same pitch. (03 Marks)

(b) During a storm, thunder is heard 7s after the lightning is seen. If the temperature of the air at the time of the storm is 25 ^OC, How far away is the storm cloud? (05 Marks)

(c) A string A is 2m long and has a linear mass density of 9 g/cm. String B has linear mass density of 18 g/cm. If the tension in both strings is the same, how far must string B be for it to be at resonance with the string A?. (07 Marks)

PRESIDENT’S OFFICE, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

SECONDARY EXAMINATION SERIES,

PRE MOCK EXAMINATION 

PHYSICS  FORM FOUR

Time: 3Hours

Instructions 

1.         This paper consists of sections A, B, and C with a total eleven (11) questions.
2.         Answer all question in the sections A, B and two (2) questions from section C.
3.         Section A carries sixteen (16) marks, section B fifty four (54) marks and section C carries thirty (30) marks.
4.         All writing should be in blue or black pen, except for diagrams that must be drawn in pencil.
5.         Communication devices and any unauthorized materials are not allowed in the examination room.
6.         Write your Examination Number on every page of your answer booklet (s

1.             The SI unit of acceleration is:

A) Meter (m)

B) Kilogram (kg)

C) Second (s)

D) Meter per second (m/s)

E) Meter per second squared (m/s²)

2.           According to Newton's Second Law of Motion, force (F) is equal to:

A) Mass (m)

B) Mass x Acceleration (ma)

C) Acceleration (a)

D) Weight (mg)

E) Work (W)

3.         An object submerged in a fluid experiences an apparent buoyant force equal to:

A) Its weight in air

B) The volume of fluid displaced by the object

C) The weight of the fluid displaced by the object

D) The density of the object

E) The density of the fluid

4.         Opposite poles of magnets attract each other, while like poles repel each other. This principle is the foundation of:

A) Electromagnetism

B) Electrostatic force

C) Nuclear force

D) Gravitational force

E) Strong force

5.           A changing magnetic field can induce an electric current in a nearby conductor. This phenomenon is described by:

A) Ohm's Law

B) Kirchhoff's Laws

C) Faraday's Law of Electromagnetic Induction

D) Lenz's Law

E) Coulomb's Law

6.         A car accelerates uniformly from rest to a speed of 20 m/s in 5 seconds. What is the car's acceleration?

A) 1 m/s²

B) 4 m/s²

C) 5 m/s²

D) 10 m/s²

E) 20 m/s²

7.       Most materials expand when heated and contract when cooled. This phenomenon is primarily due to:

A) Phase change

B) Increased atomic mass

C) Increased intermolecular spacing

D) Decrease in density

E) Change in chemical composition

8.     A convex lens can be used to:

A) Magnify objects (act as a converging lens)

B) Diverge light rays (act as a diverging lens)

C) Measure distance

D) Detect electric current

E) Separate colors of light (act as a prism)

9.         The speed of a mechanical wave depends on:

A) Its amplitude only

B) Its frequency only

C) The properties of the medium it travels through

D) The color of the wave (for light waves)

E) All of the above

10.           A diode allows current to flow through it in:

A) Both directions

B) One direction only (forward bias)

C) One direction only (reverse bias)

D) Proportion to the applied voltage

E) Independent of the applied voltage

2. Match the following geophysics terms in LIST A with corresponding description in LIST B.

3. (a) What is the refractive index for a certain medium, if the light in air enters the medium at an angle of 30° and refracted at 22°? 

(b) A vertical object 10 cm high is placed 20 cm away from a convex mirror of radius of curvature 30 cm. using a ray diagram, determine 

(i) Image distance

(ii) The height of the image formed

(iii) The magnification of the image

4. (a) Describe how a lens camera operates the same as human eye. Give three points 

(b) Briefly explain how conduction of heat can be applied in your daily life (three reasons) 

5. (a) NYAMWERU was at home cultivating. He had two hoes, sharp and blunt hoe. Blunt hoe was not cutting well as how sharp hoe did. Explain to him why sharp hoe cuts well than blunt hoe. (b) A cube of sides 2cm is completely submerged in water so that the bottom of the cube is at a depth of 10cm. find:

1.             Difference in pressure between bottom and top of the cube.
2.             Different of force between bottom and top of the cube.

6.(a) Explain why does a solid weigh more in air than when immersed in a liquid? 

2. By using a help of diagram explain what happen to the two parallel straight conductors when current is moving in the same direction and in opposite direction.
3. A block of wood of mass 5kg is placed on a rough inclined plane, at 60^° to the horizontal. If the coefficient of kinetic friction between the wood and the plane is 0.3, determine the acceleration of the wood down the plane.

7. A metal rod has a length of 2.00 meters at room temperature (20°C). When heated to 100°C, the rod expands by 1.6 mm.

a) Calculate the linear expansivity of the metal. 

b) Predict the length of the rod if it is cooled down to -10°C. 

c) Explain why bridges often have expansion joints built into their structure.

8. A car of mass 1200kg is accelerating on a straight track. The grapg below shows how the force acting on the car varies with time.

1.    Describe how the acceleration of the car will change over time.
2.    Calculate the aceleration of the car when the force is 3000 N
3.     Explain why the force needed to acelerate the car increases over time.

9.  (a) George Ohm observed that as the current flows through the circuit, it encounters some opposition. This opposition determines the amount of current flowing in electric device depending to the particular material

(i) State the law that Mr. George formulate.

 (ii) Briefly explain factors affecting resistance of a conductor observed by Mr. George Ohm to sum up his observation. 

 (b) (i) Distinguish between the concept of conductors, semiconductor and insulators in term of energy bands

 (ii) Give out one structural difference between A.C and D.C generators.

10. (a) Students of form four in Uganda were not taught about electronics. Suppose you were invited to speak to them, using a labelled diagram explain how full-wave rectification can be achieved by using two diodes and centre-tapped transformer. 

(b) (i) Electrical energy is distributed in all parts of Tanzania by the National Grid

System which transmits a.c at very high voltage. Why is an a.c and not a d.c used? 

(ii) Six cells each having an emf of 2V and internal resistance of negligible resistance, a 1.4Ω resistor and a metal-filament lamp. The ammeter reads 3A, what readings would you expect from a high resistance voltammeter connected across the battery terminals?

11. (a) When a simple pendulum displaced at a small angle swings to and fro, in this motion potential energy and kinetic energy changes by alternating each other. With the aid of diagram verify the alternation of these energies.

 (b) A 50kg girl runs up a staircase of 50 steps each step is 15cm in height in 5s. Find Work done against gravity by the girl and Power she use to run.

PRESENT’S OFFICE, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

SECONDARY EXAMINATION SERIES

COMPETENCY BASED SERIES

PHYSICS FORM FOUR

MID-TERM EXAMS – AUGUST – 2023

Time: 3 hours  

INSTRUCTIONS

1. This paper consists of section A, B and C with a total of Eleven (11) questions 
2. Answer ALL question in section A and B and Two (2) from section C
3. Section A carries sixteen (16) marks, Section B fifty-four (54) marks and section Thirty (30) marks
4. Non-programmable calculators may be used
5. Cellular phones and any unauthorized materials are NOT allowed in the examination room
6. Write your Examination number on every page of your answer sheet provided
7. Where necessary, the following constant may be used:

• Acceleration due to gravity, g = 10m/s² or 10N/kg
• Atmospheric pressure Pa = 102,000N/m²
• Density of water, ρ_w = 1g/cm³ or 1,000kg/m³
• Density of mercury, ρ_Hg = 13.6g/cm³ or 13,600kg/m³
• Specific heat capacity of water, Cw = 4,200j/kg K
• Speed of sound in air, v = 340m/s
• Pie, π= 3.14

SECTION A (16 MARKS) 

Answer ALL questions

1. For each of the items (i) – (x) choose the correct answer from among the given alternatives then write the letter of the correct answer in the answer sheets provided.

i) Which of the following apparatus is used to measure the mass of an object?

1. Spring balance
2. Triple balance
3. Pendulum balance
4. Hydrometer
5. Thermometer

ii) A piece of cork of volume 100cm³ is floating on the surface of water. If the density of the cork is 0.25g/cm³, what volume of the cork is immersed in the water?

1. 100cm³
2. 0.25cm³
3. 25cm³
4. 100.25cm³ 
5. 0.025cm³

iii) A blue T-shirt absorbs all the colour of the white light the blue

T-shirt looks

1. Red
2. Blue
3. Black
4. white
5. cyan

iv) A stone of 2kg falls from a height of 25m above the ground.

Calculate the potential energy

1. 500J
2. 279J
3. 520J
4. 390
5. 150

v) A capacitor is used to store electric charge in the form of electric field. Which of the following explains why capacitor is highly?

employed in most electronic devices and communications?

1. Capacitors are fabricated
2. Capacitors are used as filters, smoothers, indicators and clippers
3. Capacitors are cheap
4. Capacitors are not complicated in design
5. Capacitors are small in size

vi) A cube is made with equal lengths of thin copper wire. When the cube is uniformly heated from 200C to 600C

1. It expands the same amount as solid/copper cube of the same size
2. The shape changes to rectangular one
3. The lengths of the wires are doubled
4. The area of each side of the cube is double
5. The cube will twist

vii) The zigzag path travelled by an electron from negatively charged

1. Radar
2. Lightning
3. Thunder
4. Field emission
5. Ions

viii) A spiral spring of natural length 1.50m is extended to 1.505m by a force of 0.80N. What will be its extension when the applied force is 3.20N?

1. 0.005m
2. 6.020m
3. 0.020m
4. 4.520m
5. 1.57m

ix) The note from a plucked guitar will have a low pitch if the string is

1. Thick and short
2. Thick and slack
3. Thin and short
4. Thin and long
5. Thick and tight

x) What do we call the temperature scale where 273 represent freezing and 373 represent boiling point of water?

1. Fahrenheit
2. Celsius
3. Kelvin
4. Absolute
5. Angstrom

2. Match the phrases in list A with their correct responses in list B by writing the letter of the correct answer.

SECTION B (54 MARKS)

Answer ALL questions

3. Figure below shows a Hummer striking a nail in wood with a glacing (sideways) force. If the force is 60N at 60⁰ to the vertical.

a) Find the vertical component

b) What will happen if the hammer strikes the nail horizontally with a force of 60N

4. a) i) The boots for soccer and hockey player have studs on their soles. Why?

ii) The force required by man to move his limbs immersed in water is smaller than the force for the same movement in air. Why?

b) i) A conical flask with a base of diameter 7.0cm is filled to a depth of 10cm with a liquid of density 840kg/m³. Find the total force due to the liquid on the base in Newton’s.

ii) Consider a cylinder of cross section A filled with a liquid of uniform density  to a height h. a normal force acts on the bottom of the cylinder due to the weight of the liquid inside. Therefore, drive the pressure p exerted by the liquid on the bottom of the cylinder

5. a) Explain the following:

i) A person failing on a cemented floor gets more hurt than failing on a sand floor

ii) A hunter moves abruptly backwards on firing a bullet of 1kg his bullet of 10kg

b) A hydraulic press consists of a pump, load and two cylinders in which the layer cylinder is eight times the diameter of a smaller one. Use a well labelled-sectional diagram of a hydraulic press to determine the value of mechanical advantage of this machine if it is working with efficiency of 90%.

6 a) Use Newton’s second law of motion to reduce that, impulse is equal to the change of linear momentum of a body, and explain why it is necessary important to fold our legs when we jump from a height on landing.

b) Explain why it is extremely so easy to raise a cargo in water but extremely very difficult to raise the same cargo in air.

7. a) Differentiate between heat capacity from specific heat capacity. Give two points

b) A form four students at U.B.N secondary school mixed water from two pots of the same mass. One pot is at 250C and the other is at 350C. What will be the equilibrium temperature in degree centigrade?

8. a) The velocity of car B relative to car is 8m/s when the two cars are moving in the same direction and 28m/s when two cars are moving in opposite directions. Determine the velocity of each car

b) i) Why does an object appear colored when light fall on it?

ii) Explain why the result of mixing blue and yellow paints is very different from that mixing blue and yellow light.

SECTION C (30 Marks)

Answer two questions from this section

9. a) X-rays are said to have harmful effect to human being when used for long time. Explain the effects that X-rays cause to human.

b) i) Describe how x-rays are produced in x-ray tube.

ii) Explain four uses of x-rays in daily life.

10. a) State laws of electromagnetic induction

b) With reason name the following symbols. Hence state the function of each in the national grid of electricity.

11. a) Draw a well labelled diagram of cathode ray tube. Hence state two uses of the drawn diagram and two properties of rays produced in it.

b) What are the main purpose of connecting a diode and transistor on various electric devices? (Describe for each device)

PRESIDENT OFFICE REGIONAL ADMNISTRATION

AND LOCAL GOVERNMENT

SECONDARY EXAMINATION SERIES 

COMPETENCE BASED ASSEMENT

PHYSICS FORM FOUR 

TERMINAL EXAMS MAY – 2023 

031/1

TIME: 3HOURS

INSTRUCTIONS 

1. This paper consists of session A, B and C
2. Answer all questions from section A and B and only two questions from section C
3. Any unauthorized materials are not allowed in examination room.
4. Write an examination number on every page of your answer sheets
5. Where necessary, the following constant may be used:

1. Acceleration due to gravity g=10m/s²
2. 
3. S.T.P, 760mmHg, 273K

SECTION A (16 Marks)

Answer all questions in this section

1. For each of items (i) – (x) choose the correct answer from among the given alternatives and write its letter the item number in the answer sheets provided.

1. The multiple reflection of the sound produced when its travels in an enclosed room refers as

1. Sound waves
2. Transverse waves
3. Resonance
4. Echo
5. Reverberation

2. The phenomenon that causes the dispersion white light into spectrum prism:

1. Refraction
2. Deflation
3. Reflection
4. Absorption
5. Interference

3. The death of deep seas creatures is when brought shallow water. This happens because of:

1. Their pressure inside bodies is greater to the surrounded pressure of water.
2. Their pressure made inside bodies is less than that surrounded pressure of water
3. The density of dead body is equal to that of water
4. Volume of body displaced is equal to volume of water
5. Pressure of dead body is equal to that of atmospheric pressure.

4. Aluminum is used in making motor engines pistons and cylinders due to its

1. Low density and high thermal conductivity
2. Low density and low thermal conductivity
3. Its good conductor of heat than copper
4. Thermal expansivity is high
5. It’s stronger enough to maintain high temperature.

5. One of the assumptions made when demonstrating how to determine specific heat capacity of substance by the mixture method is that:

1. No heat lost to the surrounding, heat absorption by apparatus
2. Heat lost to the surrounding, heat absorption by apparatus
3. No heat lost to the surrounding, heat absorption by apparatus
4. Heat lost to the surrounding, no heat absorption by the apparatus
5. Calorimeter is apparatus for demonstrating.

6. The phenomenon of melting under pressure and re-freezing when pressure reduced is called:

1. Ebullition
2. Triple point of water
3. Regelation
4. Depression
5. Equilibrium

7. Sweeting uses the cooling effects caused by

1. Osmosis
2. Diffusion
3. Freezing
4. Evaporation
5. Saturated water

8. A lens camera of focal length 15cm is used to take a picture of a man of height 1.8M, if a man is standing 10M ahead of the camera, what is magnification of the image:

1. 1.8
2. 1.5
3. 0.00152
4. 0.00142
5. 0.005

9. Mercury from Spheroid drops when split on a wooden bench because:

1. Its velocity is very high
2. It has relative density
3. It has high cohesive force
4. It has low surface tension
5. It is subjected to high atmospheric pressure.

10. A device consists of a coil rotating in an external magnetic field to produce electricity refers as

1. Transformer
2. Electric bell
3. Spark coil
4. Generator
5. Galvanometer

2. Match the items in List A with the responses in List B by writing the letter of the correct response beside the item number of the answer sheets provided.

SECTION B (54 MARKS)

Answer all questions from this section

3. (a)Give out six differences between lens camera and human eyes.

(b)Optometrist and Ophltholmegist prescribe lenses measure in diopters, what is the power of the lens if the local lengths of the length 2M?

4. (a)Why the overhead power cables more likely to break and fall during the cold season of the year than warm season of the year, even though they carry the same weight all the year around.

(b) 250cm³ of a gas are collected at 25°C and 750mmHg; calculate the volume of gas at STP? 

5. (a) What is the meaning and functions of the following electrical devices:

(b)A cell supplies a current of 0.6A through a 2Ω through a 7Ω resistors, calculate the emf and inter resistance of a cell

6. (a)Why does the sky appear blue while being observed from the earth and black when you are on moon

(b)A solid of mass 26g absorbs 800J of heat when heated. If the initial temperature to the body is 30°C, find its final temperature.

7. (a)The handle of a screw jack is 35cm and the pitch of a screw is 0.5cm if the efficiency of the jack is 55% calculate the force required to be applied at the end of the handle to lift a load of 2300N.

(b)(i) State the factors in which pressure in liquid and solids depends on. 

(ii)In a hydraulic press the area of the piston to which the effort is applied is 5cm². If the press can raise a weight of 2KN when an effort of 400N is applied, what is the area of the piston under the load?

8. (a)A certain sample with half-life of 8days contains 16g of iodine-131.

1. Write an expression to show the decay process of the sample
2. Use an expression in (a)(i) to sketch the graph then estimate the mass of sample which will remain undecayed after 20 days

(b) Describe the mode of action of Geiger-Muller (G-M) tube in detecting nuclear radiations 

SECTION C (30 MARKS)

Answer only two questions in this section

9. (a)What is sonometer, state why guitars have string vary (thickness and thinnest) which produce the biggest frequency

(b)The frequency obtained from a plucked string 800Hz when tension is 8N. Calculate frequency when tension doubled and tension when frequency is halved?

(c)Distinguish the concepts of conductors, semiconductors and insulators in terms of their energy bands.

10. (a)Explain briefly how the concept of wave is applied in:

(i)Medicine   (ii) Communication  (iii) Scientific Research

(b)The diagram below shows displacement time graph of wave with velocity of 2m/s 

Calculate

(i)the amplitude  (ii)Frequency   (iii)Wavelength 

(c)A circuit in a house is protected by a 10A fuse. The circuit is connected to the 240V main. The following appliances are connected to the circuit:

Determine whether the fuse will blow on or off if all appliances are turned on 

11. (a)In production of x-rays what are roles of

(i)Low voltage  (ii)High voltage (iii)Tungsten target 

(b)Describe four (5) applications of friction in daily life.

(c)State laws of electromagnetic induction 

THE PRESIDENT’S OFFICE

MINISTRY OF EDUCATION, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

COMPETENCE BASED SECONDARY EXAMINATION SERIES

PHYSICS FOUR ANNUAL EXAMINATIONS

FORM FOUR-2022

Instruction 

1. This paper consists of section A, B and C with a total of eleven [11] marks
2. Answer all questions in section A and B and two [2] questions from section C
3. Mathematical table and non – programmable calculator may be used
4. Cellular phones are not allowed in the examination room
5. Write your Examination number on every page of your answer sheet provided
6. Where necessary the following constants may be used

• Acceleration due to gravity g = 10mls²
• Density  of water, p= 1000 kg /m³ or 1g/cm³

SECTION A [15 MARKS]

1. For each of the items [i] – [x] choose the correct among the given alternatives and write its letter beside the item number in the answer sheets provided.

[i]. Which one among of the following is a factor on which up thrust exerted on a body by fluid depends:

1.  Volume of the fluid   B. Mass of the fluid   C. Viscosity of the fluid D. Density of the fluid                             E. Temperature of the fluid

[ii]. A layer of colour less water is carefully floated in a cylinder  on top of blue copper sulphate solution after a time, the water becomes blue, because of? 

1. Liquid friction   B. Density changes   C. Diffusion

4. Viscosity    E. Pressure changes

[iii]. If the mass of copper over the volume of copper is 8.9g/cm³. Find the volume 89g of copper  

1. 10 ^-5 cm   C. 10^-5m³
2. 0.1 cm³  D. 100CM³   E. 10cm³

[iv]. Aluminum is used in making motor engines, pistons and cylinders due to 

1. Its low density and high conductivity
2. Low density and maximum pressure
3. High density and varying mass
4. Its high conductivity and high density
5. Its heavy weight and low conductivity

[v]. A group of stars that forms a pattern shape in the sky is called………………..

1. Tides     C. A constellation   
2. A galaxy    D. The universe   E. The milky way

[vi]A basic condition for diffraction of wave when it passes through an opening is that 

1. The wavelength of the incident wave must be greater than the size of opening
2. The amplitude of wave must be smaller than the size of opening
3. The wavelength of the most almost be the corresponding size of the opening
4. The wavelength of the wave must almost be equal to the size of the opening
5. The amplitude of the wave must be greater than the opening

[vii]. When light is totally internally reflected from the boundary of a certain transparent material and air the critical angle is found to be 50⁰ the speed of light in the material is 

1. 2.1 x 10⁸m/s   
2. 2.2 x 10⁸m/s  
3. 1.94 x 10⁸m/s

D.2.3 x 10⁸m/s   

E. 3.0 x 10⁸m/s

[viii] Why buildings are constructed with wide foundation?

1. Because of power
2. In order to reduce pressure exerted by the building on the ground
3. So as to build large house
4. To increase pressure of the ground so as to maintain holding the house.
5. To avoid earth quake

[ix]. The energy from the hot rocks within the earth is called.

1. Tidal energy
2. Water energy
3. Cool- burning energy
4. Biomass energy
5. Geothermal energy

[x]. A reference was a certain device to judge football game in 90 minutes at MKAPA arena, that device was:-

1. Football    C. Stop watch  
2. Tape measure    D. 90 Minutes   E. Line man

2. Match the functions or importance’s of the layers of the atmosphere in List A with their corresponding  features in List B by writing the letter of the correct response beside the items number in the a lower sheets provided

Section B [60 marks]

Answer all questions

3. [a]. By using well labeled diagram, explain in short why the stem of the hydrometer is made thin and weighted with mercury or lead shorts? [06 marks]

[b]. A ship is made of steel and it is expected that it should sink in water. However it does not sink. At the same time a coin once dropped in water it will sink. How can you solve this contradiction so as to help a form one student who is totally confused? [04 marks]

4. [a]. It has been found the efficiency of a pulley system is always less than 100%. Giving two reasons explain the secret behind. [04 marks]

[b]. A meter rule is pivoted at its mid-point. If two objects of weigh 1.0N and 2.0N are suspended at 30cm and 90cm respectively from one end, calculate the position 

5. [a]. State the laws of refraction of light

[b]. The diagram below shows a ray of light incident on a glass prism at an angle.

Complete the diagram to show as it emerges from the other side [05marks]

[c]. Sketch a ray diagram to show the formation of a solar ellipse [03marks]

6. [a]. Give one difference and one similarity between a fuse and a circuit – breaker  [04 marks]

[b]. A cell supplies a current of 0.6A through a 2? coil and a current of 0.2A through a                           

752? coil. Calculate the e.m.f and internal resistance of the cell [06marks]

7.  [a]. Explain on the basic of conservation of linear momentum, how a fish propels itself forward by swishing its tail back and forth [04 marks]

[b]. A block and tackle system of 5 pulley is used to raise of 490N steadily through a is then 1800 J. calculate the efficiency of the system and efforts applied  [06 marks]

8. [a]. [i].Define half – life

      [ii]. A particular radioactive has a half – life of 2 hours A sample gives a count of 2400 per second at 11:00. When will the count have dropped to approximately 300 per second in the same counting system?  [04marks]

[b].  [i]. With diagram explain the mode of action of fuse.[03marks ]

 [ii]. Mention two [2] types of diode [02 marks]

Section C [25 marks]

Answer two [2] question form this section

9. [a]. Explain why notes of the same pitch played an a violin and a flute sound different? [03marks].

[b]. Give one reason why the frequency of the fundamental may alter during the day? [03marks]

[c]. A pipe closed at one end had a length of 10cm. if the velocity of sound in the air of the pipe is 340m/s, calculate the frequency of the fundamental and that of the first overtone [06 ½ marks]

10. [a]. [i]. hat is electromagnetic induction [01marks]

      [ii]. Explain carefully how the transformer works [03 ½ marks]

[b]. Briefly explain why the core of a transformer is made of thin layers of metal insulated from one another. [02marks] 

[c]. A transformer with primary oil of 400 turns and secondary oil of 200 turns is connected to the 240 V wire mains. If the primary current is 3A and secondary current is 5A.

      [i]. Calculate the efficiency of the transformer. [04marks]

      [ii]. Give reason why would expect this efficiency to be less than 100% [01marks]

                  [iii]. What is the type of transformer? Why are you [01marks?] 

11. [a]. Draw a labeled diagram of a longitudinal section view of the cathode ray oscilloscope tube showing its main features

[b]. What are the differences between a conductor, semiconductor and insulator interms of their energy levels? [04 ½ marks]

[c]. Name four gases that contribute to global warming and give one source of each [04marks]

THE PRESIDENT’S OFFICE

MINISTRY OF EDUCATION, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

COMPETENCE BASED SECONDARY EXAMINATION SERIES

PHYSICS TERMINAL EXAMINATION

FORM FOUR-2022

INSTRUCTIONS

1.   This paper consists of sections A, B and C with a total of eleven (11)  questions.
2.    Answer all questions in sections A and B and two (2) questions  from section C.
3.    Cellular phones and any unauthorised materials are not allowed in  the examination room.
4.    Non-programmable calculators may be used.
5.    Write your Examination Number on every page of your answer  booklet(s).
6.   Where necessary the following constants may be used:

1.  Acceleration due to gravity, g = 10 m/s ²
2. Density of water = I .0 g/cm ³ 
3. Pie= 3.14.
4.  Coefficient of linear expansivity of the brick 1.2 x 10 ^-5 K ^-1
5.  Speed of light in air = 3 x 10⁸ m/s. 
6. Speed of sound in air = 340 m/s.

SECTION A (15 Marks)

Answer all questions in this section.

1. For each of the items (i) - (x), choose the correct answer from among the given alternatives and write its letter beside the item number in the answer booklet provided.

1. High voltage is used for transmitting electricity on the National Grid. This is because high voltage

1. is needed everywhere
2.  means high current would be used
3.  needs transformers for conversion
4.  would minimize electrical energy losses by using low current.
5. would facilitate power distribution to customers.

2. Polarization is

1. the cell defect caused by impurities in zinc plate
2.  the formation of hydrogen gas around the positive plate of an electric cell
3. the formation of tiny cells around zinc plate
4. the cell defect that can easily be corrected by amalgamation
5. the process of giving polarity

3.                     A transistor is a device which

1. amplifies alternating current or voltage
2. amplifies direct current or voltage
3. rectifies direct current or voltage
4. amplifies and rectifies alternating current or voltage
5. Rectifies alternating current or voltage.

4.                      What causes water tides in the sea?

1. Rotation of the earth about the sun
2. Rotation of the moon about the earth
3. Rotation of the earth about its axis
4. Gravitational force due to the earth on the sea
5. Gravitational force due to the moon on the sea

5. Which is an incorrect statement about the solar planets?

1. They are always moving in space
2. They are all non ­luminous
3. They all revolve round the sun as their centre
4. They all have at least one moon
5. The brightest planet as observed from the earth is venus.

6.                      Which of the following are inner planets?

1. Mercury and Venus
2. Jupiter and Mars
3. Saturn and Venus
4. Neptune and Uranus
5. Pluto and Mars.

7.                   One use of gamma ­rays (?rays) is to

1. treat neurotics
2. treat black spots
3. heal fractures
4. kill cancer cells
5. join broken hands.

8.                The conduction in a semi conductor material is due to

1. doping
2. extrinsic conduction
3. intrinsic conduction
4. motion of charges
5. movement of holes and electrons.

9.                      Compared to cool air, warm air can hold

1. more water vapour
2. less water vapour
3. the same amount of water vapour
4. no water vapour
5. more or less the same amount of water vapour.

10. Which of the following is correct about a capacitor?

1. Does not need an insulator between its plates
2. Has very high capacitance when air is between its plates
3. Must have metal plates to store a charge
4. Has capacitance defined by C = V/Q
5.  Has no voltage across it when working in a radio receiver.

2. Match the items in list A with the responses in list B by writing the letter of the correct response

beside the item number.

SECTION B (60 Marks)

Answer all questions in this section.

3. (A) Define the terms

(i) Half life (ii) atomic number

(b) Name the three fundamental particles of which atoms of an element are composed. How are these particles distributed in the atom of an element whose atomic number is 3 and mass

number7?

(c) A radioactive nucleus is denoted by the symbol 88X226

Write down the compositions of the nucleus at the end of the following stages of disintegration

(i) Emission of an alpha (∝) particle

(ii) Further emission of beta (β) particle

(iii) Further emission of a gamma radiation

4. (a) (i) Distinguish between mechanical and electromagnetic waves

(ii) Explain why a duck remains floating at the same place as a wave passes by the water in a lake

(b) (i) What are ultrasonic vibrations?

(ii) An FM radio station broadcasts electromagnetic waves at frequency of 125 M Hz. The radio waves have a wavelength of 2.4 metres. Calculate the speed of the radio waves

(c) Gamma ray busters are objects in the universe that emit pulses of gamma rays with high energies. The frequency of the most enegetic bursts has been measured at round 3.0 x 1021 Hz.

(i)What is the wavelength of these gamma rays?

(ii)What could be their period?

5. (a) A body projected vertically with a velocity of 40m/s from the ground, comes to rest momentarily at the top most position and returns to the ground. Calculate; (i) The maximum height reached by the body  (ii) The total time of flight

(b) In figure below, a force of 100N acts on the smaller piston of area 2cm². Calculate the upward force acting on the large piston of area 900 cm².

(c) A body of mass 400g falls freely from a tower and reaches the ground after 4s. Calculate the kinetic energy of the mass as it hits the ground. (Take g= 10m/s²)

6. (a) A machine is used to lift a load of 400N with an effort of 80N.

Calculate

1. The mechanical advantage of the machine,
2. The efficiency of the machine, if the velocity ratio of the machine is 8

(b)A spiral spring produces an extension of 4cm when a force of 2N is applied to it. Calculate the spring constant for a system when two such identical springs are arranged in (a) series (b) parallel

(c)A metal block of density 7 800kg/m³ weighs 117N in air and 105N in a liquid when wholly immersed wholly immersed. Calculate the density of the liquid.

7. (a) Name two objects in space which are the earth’s nearest neighbours

(b) What are the real names of objects in the sky which are commonly known by the following names?

(i) An evening star

(ii) A morning star

(iii) A shooting star

(c) The earth appears to be stationary, but it is always in motion. Calculate the unnoticed speed of a man along

the equator, in km/h,due to

(i). Rotational motion of the earth about its axis

(ii). Revolution of the earth around the sun

Take 1 year = 365 days

8.(a) Define the following terms.

(i) Capacitor

(ii) Semi-conductor

(iii) Transistor

(b) What are the differences between a conductor, a semiconductor and an insulator in terms of their conductivity?

(c) An output of transformer is connected in series with semiconductor diode

(i) Draw the sketch of the expected variation of electromotive force against time.

(ii) Give reasons whether this device is suitable or not for use in a radio.

9. (a) Sketch the magnetic field patterns due to a current passing through

(i) a long straight wire (ii) a circular coil (iiii) a long solenoid

Indicate clearly the direction of current and magnetic field.

(b) Explain briefly how the domain theory of magnetism is used to differentiate a magnetic material from a magnet

(c) (i) Describe how sounds are transmitted by telephones,explaining the actions of both transmitter and receiver.

(ii) What additional equipment is needed to ensure good communication over long distance?

SECTION C (10 Marks)

Answer one (1) question from this section.

10. (a) Using Newton’s second law of motion, state two quantities which vary with net force

applied on a body. (02)

(b) Write an equation obtained by combining the force and the two quantities you have

mentioned. (02)

(c) Evaluate the proportionality constant if your equation is used to define the unit of force,

the Newton, while taking a unit of each variable in your equation. (01)

(d) A certain force gives a mass m 1 an acceleration of 12.0 m/s 2 . What acceleration will the

same force give the two masses when they are joined together? (04)

11. (a) (i)Use the kinetic theory to explain why solids expand when heated.

 (ii)Mention two experiments which can be done in the laboratory to verify thermal expansion of solids. 

(b) Explain how each of the following works:

(i) a bimetallic thermostat.

(ii)a bimetallic thermometer.

(c) (i) What is an induction coil?

(ii) Describe the structure of an induction coil and briefly explain its mode of action.

THE PRESIDENT'S OFFICE

MINISTRY OF REGIONAL GOVERNMENT AND LOCAL GOVERNMENT

MID TERM-1 EXAMINATION

PHYSICS FORM-4

2022- MARCH/APRIL

TIME: 2:30 HRS

Instructions

1.   This paper consists of sections A, B and C with a total of eleven (11)  questions.
2.    Answer all questions in sections A and B and two (2) questions  from section C.
3.    Cellular phones and any unauthorised materials are not allowed in  the examination room.
4.    Non-programmable calculators may be used.
5.    Write your Examination Number on every page of your answer  booklet(s).
6.   Where necessary the following constants may be used:

1.  Acceleration due to gravity, g = 10 m/s ²
2. Density of water = I .0 g/cm³
3. Pie= 3.14.
4.  Coefficient of linear expansivity of the brick 1.2 x 10 ^-5K ^-1
5.  Speed of light in air = 3 x 10⁸ m/s. 
6. Speed of sound in air = 340 m/s.

SECTION A (15 Marks)

Answer all questions in this section.

1. For each of the items (i) - (x), choose the correct answer from among the given alternatives and write its letter beside the item number in the answer booklet provided.

(i) What physical phenomenon is observed when a tea bag is dipped into a cup containing hot water?

1.  Surface tension
2.  Capillary then diffusion
3.  Diffusion
4.  Osmosis then diffusion 
5.  Osmosis only. 

(ii) When a gas is compressed at constant temperature, the gas molecules

1.  move faster than air outside and the pressure is increased
2.  move with uniform speed and the pressure is unchanged
3.  gain more kinetic energy and the pressure is decreased
4.  increase slightly in size and its pressure remains constant
5. make more impacts per second on the walls of the container.

 (iii) A car moving at steady speed has a frictional force on its surface whose size depends on its

1.  speed and surface area
2.  speed
3.  surface area
4.  weight 
5.  wheels speed. 

(iv) A body is said to be in equilibrium IF

1. it moves with uniform speed
2. the net force acting on it is zero
3. the upward and downward forces are equal
4. its centre of gravity is low positioned
5. its centre of gravity is high.

(v) The correct statements about sound waves is that they

1. are transverse waves
2. can travel in vacuum
3. can be polarized
4. cannot be polarized
5. do not require medium.

 (vi) In order to produce electrons in a discharge tube the

1. anode should be at a higher potential than the cathode
2. potential difference at the anode should be low
3. cathode should be heated indirectly at low voltage supply
4. electrodes should be at the same potential
5. electrons must be accelerated at higher potential.

(vi)The note from a plucked guitar will have a low pitch if the string is

1. thick and long
2. thick and slack
3. thin and slack
4. thin and short 
5. thick and short.

 (vii)Lenz’s law can be applied to predict the

1. magnitude of back e.m.f. in a circuit
2. magnitude of induced current in a circuit
3. direction of applied e.m.f. across the circuit 
4. direction of induced e.m.f. in a circuit 
5. direction of the applied e.m.f. within a circuit.

(ix) In a race competition, one should kneel down when starting the race so that:

1. no one can fall down by reaction produced by the earth to them. 
2.  each one can receive an acceleration which the earth provides.
3.  one of the rules in sports is not violated by anyone.
4. equal and opposite forces can act on a body to produce a resultant force.
5. each one could exert a force on the surface of the ground.

 (x) The destruction of ozone layer in the atmosphere has led the world to disasters caused by:

1. absorption of the background radiation. 
2. poor handling of the radioactive materials.
3.  the increase of the ultra-violet radiations on the earth. 
4.  poor utilization of radioactive materials. 
5.  poor disposal methods of radioactive remains.

2. Match the functions of instruments in List A with their corresponding instruments in List B by writing the letter of the correct response beside the corresponding item number in the answer booklet provided. (5 marks)

SECTION B (60 Marks)

Answer all questions in this section.

3. (a) (i) What is meant by the term thermal expansion?

      (ii) Mention two applications of thermal expansion of solids.

(b)    (i) List three areas where bimetallic strips are used.

  (ii) Why a bimetal strip made of brass and invar is curved outside with brass?

4. (a) (i) Define the term semiconductors.

(ii) How do intrinsic semiconductors differ from extrinsic semiconductors?

b) (i) List four properties of cathode rays.

(ii) Describe how x-ray tube is used to produce x-rays.

(c) (i) Mention three uses of induction coil.

(ii) Briefly explain the working principle of a bicycle dynamo.

5. (a) Briefly explain why hydrometer 

(i) is weighed with lead shots.

 (ii) has a narrow stem.

(b)    A piece of rubber of volume 100 cm³    and the density of 0.45 g/cm³ floats in water. Calculate:

(i) The volume of rubber that partially immersed in water.

(ii) The force required to immerse the rubber completely.

6.(a) (i) Define the term wavelength.

(ii) How does the size of the gap in the barrier affect the diffraction of waves?

(b)(i) State two ways in which visible light differ from radio waves.

(ii) List two applications of gamma rays.

7. (a) (i) State the law of inertia

(ii) Use the law in (a) (i) to define force.

(b) A ticker – tape is moved through a ticker – timer for 5.0 seconds. If the timer is operating at 25 Hz:

1. How many dots would have been printed on the tape?
2. What kind of motion does the tape represent? Give a reason.

(c) A shell of mass 30kg is fired at a velocity of 600ms^-1 from a gun of mass 7000kg.

1. What is the recoil velocity of the gun?
2. Briefly explain the significance of the answer obtained in (c) (i) above.

8. (a) What is meant by the following terms?

(i) Resonance

(ii) Overtones.

(b) Briefly give reasons for the following:

(i) the fundamental frequency may alter during the day.

(ii) notes of the same pitch played on a violin and a flute sound different.

(c) The frequency obtained from a plucked string is 400 Hz when the tension is 2 N. Calculate:

(i) the frequency when the tension is increased to 8 N.

(ii) the tension needed to produce a note of frequency of 600 Hz.

9. (a) (i) What is meant by refraction of light?

(ii) Mention three points to be considered when drawing a ray diagram to show the formation of images on a concave mirror.

(b)(i)Briefly explain why part of the road ahead of a person apparently looks as if it has a pool of water on a sunny day?

(ii) A pin is at the bottom of a vessel 16 cm deep. When the vessel is filled with water the pin appears to rise when viewed form above. Find the height to which the pin appears to rise. 

(c) Paraffin has a greater refractive index than water. What can you say about the 

 (i) relative velocity of light in paraffin and in water?

(ii) path of a ray of light when passing from water into a layer of paraffin?

10. (a) Mention three differences between boiling and evaporation.

(b) Briefly explain reasons for the following:

1. When a cold bottle is brought into a warm room, it becomes misted over
2. Frost is more likely to occur on a clear night than on a cloudy night.

(b)(i) Define coefficient of linear expansion and give its SI unit.

(ii) A metal pipe which is 1 m long at 40°C increases in length by 0.3% when carrying a steam at 100°C. Find the coefficient of expansion of the metal.

11.(a) Define the following terms:

(i)Newton.

(ii)Inertia.

(iii)Linear momentum.

(b) Two stones are thrown vertically upwards from the same point with the same velocity of 20 m/s but at an interval of 2 seconds. When they meet, the second stone is rising at 10 m/s. Calculate:

(i) the time taken by the second stone in air before they meet (ii) the velocity of the second stone when they meet.

(c) A stationary bomb of mass 5 kg explodes into one part A of mass 2 kg flying off with a velocity of 60 m/s and another part B of mass 3 kg flying off with a certain velocity in the opposite direction. Calculate the

(i)velocity of part B

(ii)total kinetic energy produced by the explosion.

THE PRESIDENT'S OFFICE

MINISTRY OF REGIONAL GOVERNMENT AND LOCAL GOVERNMENT

PRE-NATIONAL  EXAMINATION SERIES-1

PHYSICS  FORM-4

2020

TIME: 3:00 HRS

Instructions

1. This paper consists of sections A, B and C with a total of eleven (11) questions.
2.  Answer all questions in sections A and B and two (2) questions from section C.
3.  Cellular phones and any unauthorised materials are not allowed in the examination room.
4.  Non-programmable calculators may be used.
5.  Write your Examination Number on every page of your answer booklet(s).
6. Where necessary the following constants may be used:

1.  Acceleration due to gravity, g = 10 m/s ²
2. Density of water = I .0 g/cm ³ 
3. Pie= 3.14.
4.  Coefficient of linear expansivity of the brick 1.2 x 10 ^-5 K ^-1
5.  Speed of light in air = 3 x 10⁸ m/s. 
6. Speed of sound in air = 340 m/s.

SECTION A (15 Marks)

Answer all questions in this section.

1. For each of the items (i) - (x), choose the correct answer from among the given alternatives and write its letter beside the item number in the answer booklet provided.

(i) Which pairs of instruments would you use to correctly measure the diameter of a small ball bearing?

1.  Measuring tape and vernier caliper
2.  Slide rule and micrometer screw gauge
3.  Vernier caliper and slide rule
4.  Micrometer screw gauge and vernier caliper
5. Metre rule and micrometer screw gauge

(ii) Which statement explains the basis of heliocentric theory?

1. The earth was known to revolve around the sun
2. The earth was stationary
3. The sun was known to revolve around the earth
4. The sun was stationary
5. The earth was known to revolve around its axis.

(iii) Which among the following is a reason for the sky to appear blue while being observed from the earth?

1. Regular reflection of sunlight
2. Irregular refraction of sunlight
3. Diffuse refraction of sunlight
4. Selective scattering of sunlight
5. Regular diffraction of sunlight.

(iv) The suspended magnetic needle always comes to rest with its axis in a vertical plane called?

1. Geographic meridian
2. Magnetic meridian
3. Geographic declination
4. Magnetic declination
5. Geographic North Pole.

(v) The correct arrangement of metals in ascending order of their linear expansivities is?

1. Iron, Copper, Invar, Brass and Nickel
2. Nickel, Brass, Invar, Copper and Iron
3. Brass, Copper, Nickel, Iron and Invar
4. Invar, Iron, Nickel, Copper and Brass.
5. Nickel, Brass, Iron, Invar and Copper.

(vi) The loudness of a note produced by a vibrating object depends on?

1. The number of vibrations per second
2. The overtones present
3. The quality of sound
4. The wavelength between two nodes
5. The amplitude of vibration.

(vii) In a black and white television, the image is formed on the screen by:

1. varying the intensity or brightness of the electron beam
2.  adjusting the number of stations using a remote control
3.  limiting the flow of electrons between the cathode and anode
4.  increasing the grid’s voltage to its maximum value
5.  adjusting the antenna to capture waves of short wavelength. 

 (viii) A green card with red flowers when viewed in a red light will appear:

1.  completely red
2.  completely yellow
3.  completely green 
4.  yellow with red flowers 
5.  green with red flowers. 

(ix) Figure 1 shows a pattern of waves in a ripple tank traveling from part X to part Y across a plane section Z.

Figure 1

What observation can be made from Figure 1?

1.  the total reflection occurs at Z
2.  the wavelength in part X is greater than that in part Y
3.  the wave speed v1 in part X is less than v2 in part Y
4.  diffraction occurs across Z
5.  The wave changes in frequency as it crosses Z. 

 (x) A solid metal cube has each side doubled to make a solid cube of the same metal eight times bigger in volume. The ration of resistivity of the new cube to resistivity of the old cube is

1.  8:1
2.  6:1
3.  1:1
4.  1:6
5.  1:8 

2. Match the items in List A with responses in List B by writing the letter of the correct response beside the item number.

SECTION B (60 Marks)

Answer all questions in this section.

3. (a) In a light experiment, a narrow beam of light directed onto a glass prism leaves the prism and falls on a white screen. Draw a labelled diagram to show the experimental set-up and observation seen on a screen. 

 4(a) (a) Why the inner core of the earth is solid while the outer core is liquid? Briefly explain.

(b) The frequency obtained from a plucked string when the tension is 2 N is 400 Hz. Calculate the frequency when the tension is increased by 6 N.

5. (a) A sample of carbon isotope ¹⁴₆C has a half-life of 5700 years. What fraction of ¹⁴₆C will remain after 11400 years?

 (b) Describe the construction and mode of action of the PN junction semiconductor.

6. (a) Briefly explain why hydrometer 

(i) is weighed with lead shots.

 (ii) has a narrow stem.

(b)    A piece of rubber of volume 100 cm³    and the density of 0.45 g/cm³ floats in water. Calculate:

(i) The volume of rubber that partially immersed in water.

(ii) The force required to immerse the rubber completely.

7. (a) (i) Define the term astronomy.

  (ii)Enumerate three importance of astronomy to mankind.

(b)    (i) Specify the difference that exists between galaxy and a planet. (ii) Outline three defining characters of a planet. 

8. (a) (i) What is meant by the term thermal expansion?

      (ii) Mention two applications of thermal expansion of solids.

(b)    (i) List three areas where bimetallic strips are used.

  (ii) Why a bimetal strip made of brass and invar is curved outside with brass?

SECTION C (25 Marks) 

Answer two ( 2) question from this section. 

9. (a) (i) Define turning effect of force and give its SI unit.

(ii) How the moment of force can be increased considerably in practical life? Give two examples.

(b) (i) List two factors that affect stability of a body

(ii) Briefly explain why the handle of a door is near its outside edge?

10. (a) What is meant by the following terms?

(i) Asteroids.

(ii) Astronomy.

(b) Distinguish between:

(i) Constellations and a galaxy.

(ii) Meteor and meteorites.

(c) (i) Mention two types of tides.

(ii) With the aid of diagram, describe how ocean tides are formed.

11 (a) (i) Define the term semiconductors.

(ii) How do intrinsic semiconductors differ from extrinsic semiconductors?

(b) (i) List four properties of cathode rays.

(ii) Describe how x-ray tube is used to produce x-rays.

(c) (i) Mention three uses of induction coil.

(ii) Briefly explain the working principle of a bicycle dynamo.

THE PRESIDENT’S OFFICE MINISTRY OF EDUCATION, LOCAL ADMINISTRATION AND LOCAL GOVERNMENT

PHYSICS- POST-MOCK- EXAMINATION-JUNE

FORM FOUR

Time 3:00 Hours JUNE 2020

1. This paper consists of sections A, B and C.
2. Answer all questions in sections A and B and one (1) question from section C.
3. Calculators and cellular phones are not allowed in the examination room.
4. Write your Examination Number on every page of your answer booklet(s).
5. Where necessary the following constants may be used:

• Acceleration due to gravity, g = 10 N/kg or 10 m/s²
• Density of air = 1.2 kg/m³
• Density of mercury = 13200 kg/m³
• Density of water = 1000 kg/m³
• Linear expansivity of steel = 11 x 10^-6 K^-1
• Pi, π = 3.14

SECTION A (15 Marks)

Answer all questions in this section.

(i) Which pairs of instruments would you use to correctly measure the diameter of a small ball bearing?

1. Measuring tape and vernier caliper
2. Slide rule and micrometer screw gauge
3. Vernier caliper and slide rule
4. Micrometer screw gauge and vernier caliper
5. Metre rule and micrometer screw gauge

(ii) A layer of colorless water floating on a blue copper (II) sulphate solution becomes blue after sometime. Which physical process supports the observation made?

1. Diffusion
2. Cohesive
3. Surface tension
4. Adhesive
5. Osmosis

(iii) Which phenomena is a result of the earth being exactly along the same line between the centre of the sun and the moon?

1. Lunar eclipse
2. Penumbra
3. Solar eclipse
4. Umbra
5. Reflection

(iv) A body moved upward a distance of 20 m. Calculate the time taken to reach the maximum height.

1. 2 s
2. 5 s
3. 10 s
4. 15 s
5. 11 s

(v) Which factors influence friction between tyres of a car moving with constant speed and surface of the road?

1. Weight and speed
2. Speed and nature of the surface
3. Nature of the surface and weight
4. Surface area of the tires and speed
5. Acceleration and nature of the surface

(vi) When the sun shines on the dark-coloured driving wheel of a car, the wheel feels warm. Why?

1. It is because the sun warms the car by induction.
2. It is because the sun gives energy to the wheel by convection.
3. It is because the sun radiates thermal energy to the wheel.
4. It is because the sun conducts thermal energy to the wheel.
5. It is because the sun conducts thermal energy to the wheel.

(vii)Which one is a characteristic of a plane mirror?

1. It forms image which is real and opaque.
2. It forms an image which is larger than the object.
3. It forms an image which is real and laterally inverted
4. It forms an image which has the same size as the object.
5. It forms an image which is smaller in size than the object.

(viii) What quantity of heat is required to raise the temperature of 25 kg sample of mercury from 20°C to 30°C?

1. 1,743,750J
2. 348,750J
3. 345,750J
4. 413,750J
5. 1,550,750J

(ix)What role does the iris play in the human eye?

1. To hold the lens in position.
2. To prevent internal reflection.
3. To control the size of the pupil.
4. To control the thickness of the lens.
5. To protect the eye from light.

(x) What will be the resistivity of a wire 2 metres long with a cross-sectional area of 0.50 mm² and a resistance of 2.20?

1. 5.5 x 10^-7 ?m
2. 6.5 xlO^-7?m
3. 2.3 x 10^-7 ?m
4. 1.1 x 10-⁶?m
5. 5.5 x 10^-6?m.

(ix)Where are asteroids found in the solar system?

1. Between Mercury and Venus
2. Between Earth and Mars
3. Between Mars and Jupiter
4. Between Saturn and Uranus
5. Between Neptune and Pluto

(x) What fraction of the atoms would have been disintegrated in 72 hours when the half-life of an element is 24 hours?

1. 1/8
2. 1/2
3. 3/4
4. 7/8
5. 1/4

2. Match the items in List A with responses in List B by writing the letter of the correct response beside the item number in the answer booklet provided.

SECTION B (60 Marks)

Answer all questions in this section.

3. (a) Mention four applications of thermal expansion of solids.

(b) Briefly explain why holes are left below the chimneys of kerosene lamp or kitchen.

(c) A steel tyre of diameter 150 cm at 10°C is to be fitted on to a train wheel of diameter 151 cm. What temperature must the tyre be heated to just fit the wheel?

4.(a) (i) Define the term wavelength.

(ii) How does the size of the gap in the barrier affect the diffraction of waves?

(b)(i) State two ways in which visible light differ from radio waves.

(ii) List two applications of gamma rays.

5. (a) (i) What is meant by mutual induction.

(ii) Illustrate how the right hand grip rule is used to determine electric current and magnetic field directions.

(b) (i) Draw the diagram of direct current (d.c) generator showing its important parts.

(ii) Briefly explain how simple a.c dynamo can be converted to simple d.c dynamo.

6. (a) (i) Define turning effect of force and give its SI unit.

(ii) How the moment of force can be increased considerably in practical life? Give two examples.

(b) (i) List two factors that affect stability of a body

(ii) Briefly explain why the handle of a door is near its outside edge?

7. (a) (i) State the law of inertia

(ii) Use the law in (a) (i) to define force.

(b) A ticker – tape is moved through a ticker – timer for 5.0 seconds. If the timer is operating at 25 Hz:

1. How many dots would have been printed on the tape?
2. What kind of motion does the tape represent? Give a reason.

(c) A shell of mass 30kg is fired at a velocity of 600ms^-1 from a gun of mass 7000kg.

1. What is the recoil velocity of the gun?
2. Briefly explain the significance of the answer obtained in (c) (i) above.

8. (a) What is meant by the terms

1. Bimetallic strip
2. Linear expansivity of the solid

(b) Briefly explain on the following observations:

1. In cold weather the metal blade of a knife feels cooler than the wooden handle.
2. A cool breeze blows from the sea on a hot summer day.

(c) (i) Define latent heat of fusion of a substance

(ii) A copper block of mass 0.68 kg is suspended in a freezing mixture at - 50 for some time and then transferred to a large volume of water at 0 . Calculate the mass of ice formed.

9. (a) Briefly explain why hydrometer

(i) is weighed with lead shots.

(ii) has a narrow stem.

(b) A piece of rubber of volume 100 cm³ and the density of 0.45 g/cm³ floats in water. Calculate:

(i) The volume of rubber that partially immersed in water.

(ii) The force required to immerse the rubber completely.

SECTION C.
Answer one question.

10. (a) (i) What is meant by the term thermal expansion?

(ii) Mention two applications of thermal expansion of solids.

(b) (i) List three areas where bimetallic strips are used.

(ii) Why a bimetal strip made of brass and invar is curved outside with brass?

(c) Describe how simple fire alarm system operates.

11. (a) (i) Define the term semiconductors.

(ii) How do intrinsic semiconductors differ from extrinsic semiconductors?

b) (i) List four properties of cathode rays.

(ii) Describe how x-ray tube is used to produce x-rays.

(c) (i) Mention three uses of induction coil.

(ii) Briefly explain the working principle of a bicycle dynamo.

031

THE PRESIDENT’S OFFICE
REGIONAL ADMINISTRATION AND LOCAL GOVERMENT
 FORM FOUR MID TERM EXAMS

PHYSICS

TIME: 3 HOURS                                                                                                                                           2020

INSTRUCTIONS

1. This paper consists of sections A, B, and C.
2. Answer all questions in sections A and B and one(1)question from section C.
3. Calculators and cellular phones are not allowed in the examination room.
4. Write your Examination Number on every page of your answer booklet(s).
5. Where necessary the following constants may be used:

Acceleration due to gravity, g = 10m/s²

Density of water = 1.0 g/cm³

Linear expansivity of iron = 1.24×10^­5K^-1 Specific latent heat of fusion of ice = 336J/g Velocity of sound in air = 340m/s

Pi, = 3.14

SECTION A (30 MARKS) 
  Answer all questions in this section.

1. For each of the items (i)­(x), choose the correct answer among the given alternatives and write its letter beside the item number in the answer booklet provided.

(i) A spiral spring of natural length 1.50m is extended to 1.505m by a force of 0.80N

What will be its extension when the applied force is 3.20N?

A. 0.005m                                         

B. 6.020m                                         

C. 0.020m

D. 4.520m                                                      

E. 1.57.

(ii)            Which of the following electromagnetic waves is used to detect flaws and defects in

steel plates?

A. infrared waves                                           

B. ultraviolet waves                         

C. x­rays

D. gamma rays                                                                                 

E. micro waves.

(iii)           A part of human eye that corresponds to the film in a camera is called

A. cornea                                          

B. iris                                                 

C. lens

D. pupil                                                            

E. retina.

(iv)           The sun generates its energy by a process called

A. thermonuclear fission                                                                    

B. thermonuclear fusion

C. geothermal energy                                                                                                   

D. geothermal fusion

E. geothermal fission.

(v)            What will be the size of the image formed if an object 4cm tall is placed 20cm in

front of a concave mirror of focal length 15cm?

A. 60cm                                             

B. 40cm                                             

C. 24cm

D. 12cm                                                         

E. 3cm.

(vi)           What is the main function of step up transformer?

A. To change a.c to d.c current                                                                             

B To decrease resistance in a circuit

C. To increase a.c voltage                                                                     

D To decrease a.c voltage

E. To increase a.c current.

(vii) The most probable radiation forming a well­defined track when passed in a cloud chamber is called

A. Gamma­rays                                               

B. Beta rays                                                      

C. Cathode rays

D. Alpha rays                                                                        

E. X­rays.

(viii) The effect of adding an acceptor impurity to a silicon produce a crystal called 

A. P­type 

B. N­type 

C. PN­type

D. NP­type                                                                                    

E. PNP­type.

(ix)           Colours are produced when white light passes through glass prism

Because;

 A          Light waves interfere glass prism

 B.       Colours the light.

 C.       In glass different colours travel at different speeds.

 D.      Different colours are filtered

E.       Diffraction of light occurs.

(x)                       Which of the following statements is true when the resistance, R, of a wire
                  is measured using an ammeter, voltmeter and rheostat?

1. The ammeter is in parallel with R
2. The voltmeter is in series with R
3. A graph of V against Ihas a gradient equal to R
4. A graph of Iagainst V has a gradient equal to R
5. The rheostat is in parallel with R.

2. Match the times in List Awith responses in List B by writing the letter of the correct response beside the item number in the answer booklet provided.

SECTION B. 60 MARKS

3. (a) In a light experiment, a narrow beam of light directed onto a glass prism leaves the prism and falls on a a white screen. Draw a labeled diagram to show the experimental set-up and observation seen on a screen.

(b) Explain two ways in which lens cameras differ from human eye.                                                         ( 10 marks)

4.     (a) (i)What effect does an increase in temperature have on the density of most liquids?( 1mark)

       (ii) Explain the procedure of using methylated spirit, water and a pendulum bob to   find the relative density of spirit.                                                                                                                                                             ( 2marks)

        (ii) Briefly explain why does a ship sink deeper in fresh water than in sea water?       ( 2marks)

1. When a piece of wood is put in a graduated cylinder containing water, the level of      the water rises from 17.7cm³to 18.5cm³. Calculate the
2. Mass of a piece of wood.
3. Total volume of a piece of wood given that its relative density is 0.60.                       (3 marks)

5. (a) Define the following terms:

1. Coefficient of superficial expansion.                                                                  (1 mark)
2. Anomalous expansion of water.                                                                          ( 1 mark)

1. (i)How much heat is needed to change 340g of ice at 0°C to water at 0°C?      ( 2marks)             
2. (ii) What is the name of heat lost by ice in (b) (i) above?                                    ( 2marks)

                                                                                                                                                                                                                             radius 8.92mm at 20°C. What temperature must the rivet be heated in order to fit                                         into the hole?                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  ( 4 marks)

               6. (a) (i)State two ways in which the image formed in plane mirror differs from that in a pin hole camera.(2marks)

     (ii) What is the effect of moving the pinhole camera closer to the object?                    ( 1marks)

      (ii) Give two similarities and two differences that exist between the human eye and a lens camera.

( 2marks)

1. A mirage is often seen by a motorist as a pool of water on the road some distance ahead.
2. Draw a sketch diagram to show the formation of such a mirage.               (1mark)
3. Briefly explain how mirage is formed.                                                                          ( 1mark)

            7. (a) (i)What is meant by the internal resistance of a cell?                                                      (1 mark)

                          (ii) Distinguish between a cell and a battery.                                                                          ( 2marks)

         (ii) Identify three disadvantages of a Leclanche cell over a lead­acid accumulators.

                                                                                                                                                   ( 3marks)

1. The current of 3.0A passes through a coil of resistance 5? connected to the terminals of a cell of constant e.m.f, E (Volt) and internal resistance, r (ohm). If a uniform wire of length, L (cm) is joined across the ends of a 5? coil to form a parallel arrangement of resistance 4? , the current is reduced to 0.25A. Determine the
2. internal resistance of a cell.                                                       ( 1 mark)
3. e.m.f of a cell.                                                                             ( 1 mark)

8. (a) (i) Define nuclear fission.                                                                                                ( 1mark)

(ii) Mention two products of nuclear fission.                                                                         ( 2marks)

(b) Figure 1 shows a comparison of the penetrating power of three types of radiations.

Figure 1

1.      Identify the name of radiations represented by the letters A, B and C.                     ( 1 mark)
2. Write two properties of each type of radiation named in 8 (b) (i).                    ( 1 mark)
3. What effect does the radiation B has on the nucleus of an atom?                              ( 1 mark)

 (c) Complete the following equations and for each name the type of decay.

1. ²²⁶88Ra ?  --------+ ²²²86Rn .______                                                                                 ( 2marks)
2. ²²²86Rn ? 2 ?1⁰e +----------------                                                                                                 (2 marks)

SECTION C (25  Marks) 

Answer TWO questions from this section.

9. (a) What is meant by;

1. Asteroids                                                                                                                                ( 2 marks)
2. Astronomy                                                                                                                             ( 2 marks)

(b) Distinguish between the following terms;

1. Constellations                                                                                                                        ( 2 marks)
2. Meteor and meteorites                                                                                                         ( 2 marks)

( c) (i) Mention two tides of tides                                                                                            ( 2 marks)

  (ii) With aid of diagram, describe how ocean tides are formed.                            ( 6 marks)

10. (a) (i) List four main parts of a ripple tank.                                                                     ( 4 marks)

(ii) What role does a stroboscope play in a ripple tank experiment?                                  ( 2 marks)

(ii) What does a violinist do to change the note emitted by a particular string?                ( 1/2 marks)

            (ii)      Calculate the frequency of vibration in a resonance tube of shortest length

of 0.22m when the next resonance length is 0.47m.                                                                         ( 2 marks)

11. (a) (i)State the functions of the hair springs in a moving coil galvanometer.               ( 2 marks)

               (ii) Explain why moving coil galvanometer is unsuitable for measuring alternating currents.

( 2 marks)

(ii) What would happen on the pattern if a.c were used instead of d.c? ( 2 marks)

(ii) An electric motor is connected by cable to a generator and produce a current of 10 A at 240V. Calculate the resistance of the cable.                                                                                       ( 2¹/₂ marks)