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)

Duration: 3 Hours Year: 2025

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. Section A carries sixteen (16) marks, section B fifty four (54) marks and section C thirty (30) marks.
4. Communication devices 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:
   1. Acceleration due to gravity, g = 9.8 N/kg.
   2. Density of water, ρ = 1000 kg m⁻³.
   3. Pi, π = 3.14.
   4. Specific heat capacity of water = 4200J/kg °C.

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. 

(i) Which of the following ways as applied in Physics can be used by one person to convey the message to another person who is in the nearby village in the form of writings?

1. Electronic mails
2. Fiber optics
3. Headphones
4. Radio waves
5. Cables

(ii) Carefully study logical steps 1 to 8 and then answer the question that follows:

1. Formulating a testable hypothesis
2. Data interpretation
3. Performing an experiment
4. Problem identification
5. Drawing conclusion
6. Asking questions
7. Data presentation
8. Data collection and analysis

Which steps show the best logical sequence for scientific investigation?

1. 8, 7, 6, 5, 4, 3, 2, 1
2. 8, 6, 4, 2, 7, 5, 3, 1
3. 4, 6, 1, 3, 7, 8, 2, 5
4. 4, 6, 1, 3, 8, 2, 7, 5
5. 6, 4, 1, 3, 8, 2, 7, 5

(iii) Which precaution should be taken to avoid false reading before using a micrometer screw gauge in measuring lengths?

1. The thimble and ratchet should be correctly handled to get rid of mismatch.
2. The faces of anvil and spindle should be wiped clean to remove any dirty particles.
3. The sleeve and thimble should be wiped clean to remove any dirty particles.
4. The anvil and ratchet should be adjusted correctly to get rid of zero error.
5. The sleeve and thimble should be held tight on their frame to get rid of parallax error.

(iv) Why a person cannot push a car from inside when it is stuck in the mud or sand?

1. Outside the car, the friction force between the legs and ground produces backward force.
2. Inside the car, the friction force between the legs and car produces less forward force.
3. Inside the car, the friction force between the legs and car produces backward force
4. Outside the car, the friction force between the legs and ground produces forward force.
5. Outside the car, the friction force between the legs and the car produces forward force.

(v) Which action will increase the density of a substance?

1. Increasing the mass of the substance while increasing its volume.
2. Increasing the volume of the substance while its mass kept constant.
3. Decreasing the mass of the substance while decreasing its volume.
4. Increasing the mass of the substance while fixing its volume.
5. Increasing the mass of the substance while decreasing its volume.

(vi) A drop of water spreads on the surface of a smooth tiles while an equal sized drop of honey refuses spreading. Why are these wonders taking place?

1. Water has more cohesive force than honey
2. Water has more adhesive force than honey
3. Honey has more cohesive force than water
4. Honey has more adhesive force than water
5. Water has less adhesive force than honey

(vii) When a sharp pencil of 5 g is placed on your hand on its tip, it will exert pressure on the hand. Calculate the maximum pressure the pencil will exert to you if it has dimensions shown in Figure 1.

Figure 1

1. 1.59 × 10⁶ Pa
2. 1.59 × 10³ Pa
3. 2.55 × 10³ Pa
4. 2.55 × 10⁹ Pa
5. 2.55 × 10⁵ Pa

(viii) An object of 5 cm is placed 25 cm away from the concave mirror of radius of curvature 24 cm. Deduce the position and characteristics of the image formed.

1. 23.1 cm, real, inverted and diminished
2. 23.1 cm, real, inverted and magnified
3. 25.0 cm, real, upright and diminished
4. 25.0 cm, real, upright and magnified
5. 23.1 cm, virtual, inverted and diminished

(ix) Suppose an engine raises 200 kg of water steadily through a height of 60 m in 20s. If the upward force used is equal to the weight of water raised, calculate the power in kW.

1. 4 kW
2. 5.88 kW
3. 3 kW
4. 5 kW
5. 7 kW

(x) Which one of the following alternatives will decrease the capacitance of the variable parallel capacitor in a radio receiver if the dielectric materials remain constant?

1. Decrease the separation and increase the area of the plates of the capacitor
2. Increase the separation and increase the area of the plates of the capacitor
3. Increase the separation and decrease the area of the plates of the capacitor
4. Decrease the separation and decrease the area of the plates of the capacitor
5. Decrease the separation and maintain the area of the plates of the capacitor