THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA

CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

031/1 PHYSICS 1

(For Both School and Private Candidates)

Time: 3 Hours Year: 2023

Instructions

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

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

Communication devices and any unauthorized materials are not allowed in the examination room.

Non-programmable calculators and mathematical tables may be used.

Write your Examination Number on every page of your answer booklet(s).

Where necessary the following constants may be used:

Acceleration due to gravity, g = 10 m/s^{2}.

Linear expansivity of aluminium = 0.00003 per ^{°}C.

Linear expansivity of steel = 0.00001 per ^{°}C.

Pie, π = 3.14.

SECTION A (16 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, (10 marks)

(i) A study that deals with constellation, solar system and cosmos is referred to as

Electromagnetism

Structure and properties of matter

Light

Astronomy

Geophysics

Choose Answer :

(ii) Which of the following burning medium requires a carbon dioxide extinguisher?

Organic solids

Flammable liquids and greases

Flammable gases

Combustible metals

Electrical hazards

Choose Answer :

(iii) The initial volume of a liquid in a burette was 57 cm^{3}. If X cm^{3} of the liquid was poured out of the burette and the final volume of the liquid remaining was 23 cm^{3}, calculate the value of X.

80 cm^{3}

50 cm^{3}

34 cm^{3}

46 cm^{3}

-46 cm^{3}

Choose Answer :

(iv) Classify the force experienced when a metal solid or a hard object is twisted.

Compression

Stretching

Restoring

Torsion

Friction

Choose Answer :

(v) Calculate the relative density of an object that weighs 3.5 N when in air and 2.8 N when fully immersed in water.

0.8

6.4

5.0

0.22

3.5

Choose Answer :

(vi) Why can water striders and pond skaters walk on water without sinking?

Because of the process of osmosis

Because of the property of capillarity

Because of the presence of impurities in water

Because of the force of surface tension

Because of the force of cohesion and adhesion.

Choose Answer :

(vii) Identify the statement that describes the Pascal's Principle of transmission of pressure in fluids.

Pressure is equally transmitted in liquid.

Pressure is the ratio of force to area.

Pressure depends on the height of the liquid column.

Pressure is affected by the force of gravity.

Pressure produces upthrust.

Choose Answer :

(viii) Suppose an engine raises 200 kg of water steadily through a height of 60 m in 20 sec. The upward force used is equal to the weight of water raised. Calculate the power in kW.

6 kW

3 kW

5 kW

7 kW

4 kW

Choose Answer :

(ix) The following statements about magnetic lines of force are correct except:

Always form close loops.

Start at north pole and end at the south pole.

Cross one another.

Stronger where the lines are closer together.

Pass through all materials, both magnetic and non-magnetic.

Choose Answer :

(x) What is the distance and displacement covered by an athlete who runs 100 m to the North, 70 m to the East, 100 m to the South and 70 m to the West to complete the race?

Distance is 0 m and displacement is 340 m

Distance is 340 m and displacement is 0 m

Distance is 340 m and displacement is 340 m

Distance is 0 m and displacement is 0 m

Distance is 700 m and displacement is 700m

Choose Answer :

2. Match the properties or functions of the simple machines in List A with their corresponding names of the machines in List B by writing the letter of the correct response beside the corresponding item number in the answer booklet provided.(6 marks)

List A

List B

(i) Is useful in drawing water from a borehole.

(ii) Applies the principle of first class lever.

(iii) Its velocity ratio increases by increasing the length of the ramp.

(iv) The effort is between the load and fulcrum.

(v) Operates based on the principle of transmission of pressure in fluids.

(vi) Carries objects from one point to another horizontally.

(b) A camera is used to take a close-up picture of an object 3 cm tall. If the object is positioned 24 cm in front of the lens and a focused image is formed on the film 12 cm behind the lens, determine the focal length of the camera lens and the height of the image formed on the film. (6 marks)

(b) A force of 200 N and 20 cm long spanner and 150 N and 30 cm long spanner were separately used to loosen the left and right front car tire nuts, respectively. Show that the 30 cm long spanner will be more effective than the 20 cm long spanner (5 marks)

(b) Figure 1 shows two simple machines A and B having the same efficiency. Justify that simple machine A requires minimum effort to raise a load of 5000N. (5 marks)

6. (a) Figure 2 shows a bimetallic thermostat strip used to regulate the temperature of the room by using a heater and a cooler. Which device between A and B is a heater? Justify your answer. (4 marks)

(b) With the aid of a diagram, compare the penetrating ability of the three types of radiations on a piece of paper, aluminum sheet and lead block.(5 marks)

9. (a) By drawing circuit diagrams supported by the graphs, compare the charging and discharging processes of a capacitor given that you are provided with a cell (E), a voltmeter (V), a switch (S), a capacitor (C), a resistor (R) and connecting wires.(6 marks)

(b) Two wires A and B of the same material and length have the cross-sectional area in the ratio 2:1. If the same potential difference is applied across each wire, comment on the amount of current flowing between the wires A andB. (6 marks)

(b)When a speaker is brought near to a Television (TV) operating using cathode ray tube, the picture on the screen is affected but when taken away, the picture becomes normal. Account for this observation. (5 marks)

(c) Transistor is a three terminal device that is used to amplify the strength of weak signals. Draw the NPN transistor circuit connections with four terminals in the following modes: Common Base (CB), Common Emitter (CE) and Common Collector (CC) indicating the input and output circuits.(6 marks)

11. (a) The shortest length of the air column in a resonance tube with one end closed and the other end open which resonates to a note of frequency 500 Hz is found to be 160 mm. Calculate the shortest length of the column of air which resonates in similar conditions to a note of frequency 800 Hz. (5 marks)