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: 2021

Instructions

l . 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. Section A carries fifteen (15) marks, section B sixty (60) marks and section C carries twenty five (25) marks.

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

5. Non-programmable calculators and mathematical tables may be used.

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

7. Where necessary the following constants may be used:

(i) Acceleration due to gravity, g = 10 m/s^-2

(ii) Density of water, p = 1000 kg/m³ 

(iii) Pie, 3.14.

(iv) Linear expansitivity of steel =  1.1 x 10^-5K^-1

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. (10 marks)

(i) How can the density of a stone with mass X when in air and volume Y when fully immersed in water be found?

1. By dividing the reduced mass of the stone to the volume of the water displaced.
2. By dividing the mass of the stone in the air to the volume of the water displaced.
3. By dividing the apparent mass of the stone in the water to the volume of the water displaced.
4. By dividing the mass of the stone in air to the upthrust.
5. By dividing the apparent mass of the stone to the upthrust.

(ii) Which property of concave mirrors is suitable for a dentist to consider when selecting concave mirrors for repairing dental related activities?

1. The one that produce diminished images.
2. The one with wider field of view.
3. The one which produce virtual and erect image.
4. The one that produce larger magnification.
5. The one in which objects and images are seen easily.

(iii) Which one of the following is not a property of magnetic lines of force?

1. Are continuous and always form closed loops.
2. Start at the north pole and end at the south pole.
3. Never cross one another.
4. Enter or leave a magnetic material at right angles to the surface.
5. Pass through magnetic materials only.

(iv) Which velocity-time graph represents the ball thrown vertically upwards and returning ground?

(v) Which statement describes the difference between maximum thermometer and minimum thermometer?

1. Maximum thermometer uses mercury while minimum thermometer uses alcohol.
2. Maximum thermometer measures the temperature of the solid object while minimum thermometer measures the temperature of the liquid.
3. Maximum thermometer measures the temperature in Kelvin while minimum thermometer measures the temperature in degree centigrade.
4. Maximum thermometer has concave meniscus while minimum thermometer has convex meniscus.
5. Maximum thermometer has index below the meniscus while minimum thermometer has index above the meniscus.

(vi) Choose the properties which correctly describe the hydroelectric energy from the following properties.

(1) Energy is virtual available

(2) Not reliable

(3) Environmental friendly

(4) Turn turbine to drive generators

1. (2), (3) and (4) 
2. (1), (2) and (4) 
3. (1), (3) and (4) 
4. (2), (3) and (4)
5. (1) , (2) and (3)

(vii) Why do people prefer white shawl to wrap around a baby to keep the baby warm?

1. White shawl is a poor conductor.
2. White shawl indicates cleanliness.
3. White shawl is the poor radiator.
4. White shawl has pockets of air trapped in it. 
5. White shawl is a good reflector of heat.

(viii) Which statement about a wet-and-dry bulb hygrometer is correct?

1. Wet bulb thermometers measure the temperature of the surrounding air.
2. The temperature recorded by a wet-bulb thermometer is always larger than that recorded by a dry-bulb thermometer.
3. When the difference in temperature recorded by wet and dry-bulbs is larger no water evaporates.
4. The value of relative humidity is low when the temperature of wet and dry bulbs is the same.
5. Wet-bulb is cooled by the process of evaporation of water.

(ix) The following diagram shows a cathode ray oscilloscope. Which conditional change on the oscilloscope can lead into producing a brighter trace on the screen?

1. Using time-base and connect alternating voltage to Y-plates
2. Increasing the anode voltage
3. Switching off time-base and connect battery to Y-plates
4. Switching off time-base and connect alternating voltage to Y-plates 
5. Using time base only

(x) Which statement distinguishes gravity from gravitational force?

1. Gravity is the force that pulls objects towards the earth while gravitational force is the attractive force existing between any two objects.
2. Gravity is the force of attraction between two objects while gravitational force is the force acting to pull objects toward the earth.
3. Gravity is sometimes called universal gravitation while gravitational force is also called centripental force.
4. Gravity is applicable from the largest stars to the smallest atoms while gravitational force does not.
5. E Gravity holds planets to revolve around the sun while gravitational force does not hold planets.