THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA F0RM Two NATIONAL ASSESSMENT

031 PHYSICS

Time: 2:30 Hours Year: 2023

Instructions

1. This paper consists of sections A, B and C with a total of ten (10) questions.
2. Answer all questions in the spaces provided.
3. All writing must be in blue or black ink except drawings which must be in pencil.
4. Communication devices and any unauthorized materials are not allowed in the assessment room.
5. Write your Assessment Number at the top right corner of every page.
6. Where necessary the following constants may be used:

(i) Acceleration due to gravity, g = 10 m/s² (ii) π= 3.14

SECTION A (15 Marks)

Answer all questions in this section.

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

(i) A student has an urgent message to send to his/her parents far from school. Which means can be the best?

1. Landline and mobile phone
2. Microphone and telephone
3. Megaphone and Mobile phone
4. Megaphone and Microphone

(ii) What is the usefulness of laboratory rules when carrying out experiments in the Physics laboratory?

1. Making students enjoy science
2. Helping students conduct experiment freely
3. Ensuring safety in the laboratory
4. Enhancing communication with other technicians

(iii) Why does a piece of steel sink in water but a steel ship floats? 

1. The density of the steel ship is less than the density of water 
2. Steel is denser than the steel ship
3. Steel ship has the same density to that of steel
4. The average density of the steel ship is less than the density of water

(iv) Which of the following is a set of effects of forces exerted when you are riding a bicycle?

1. Compressional, viscosity and stretching 
2. Torsional, attraction and couple
3. Frictional, couple and pulling
4. Attraction, friction and restoring

(v) A hydrometer is an instrument for measuring the density or relative density of a liquid. What are you supposed to do in order to increase its sensitivity? 

1. Increasing the size of the large bulb
2. Making the stem narrower
3. Reducing the lead shots in the weighted bulb 
4. Increasing the length of the stem

(vi) How can you make a rough measure of the size of a molecule?

1. By measuring the height to which water rises in a narrow capillary tube
2. By finding the speed with which Brownian vapour spreads in air
3. By observing Brownian motion of smoke particles
4. By measuring the area of the cycle in which a small drop spreads in water

(vii) A boy wants to lift a bucket full of water using a handle of metal. Which form of a handle should he use to lift the bucket comfortably? 

1. Thick handle
2. Thin handle
3. Long handle
4. Sharp handle

(viii) Which of the following is a set of natural sources of light?

1. Sun, Star and Fluorescence light
2. Sun, Star and Lightning
3. Star, Candle and Bioluminescence fly
4. Star, Lightning and Wood fire

(ix) Which statement is true about a ball falling freely from a height of 10 m?

1. Its potential energy increases but kinetic energy decreases
2. Its potential energy is equal to the kinetic energy
3. Its potential energy is zero and kinetic energy is maximum 
4. Its potential energy decreases and kinetic energy increases

(x) Which method is preferred to use if a student wishes to charge an uncharged body by using a positively charged body in order to make it acquire positive charge? 

1. Friction 
2. Contact
3. Induction
4. Heating

2. Match the uses of instruments in List A with a correct name of the instrument in List B by writing a letter of the correct response below the item number in the table provided.

Answers

SECTION B (70 Marks)

Answer All Questions In This Section

3. (a) Describe three ways in which magnets can be destroyed.

(b) Using vivid examples, Identify four applications of magnets in our daily life.

4. (a) What is the function of the construction in a clinical thermometer

(b) Explain the principal on which a liquid-in-glass thermometer works.

(c) At what temperature do Fahrenheit and Celsius scale give the same reading? 

5. (a) Suppose you find a man along the road pushing a motor cycle and it accelerated, but the same man pushed a car and failed to move it. Why the man failed to push the car? Briefly explain. (2.5 marks)

(ii) An object in a state of rest or moving with uniform motion has no forces acting on it. Argue against this statement. (2.5 marks)

(b) A car with a mass of 350 kg moving from Kondoa to Babati at a speed of 120 km/hr overtakes a bus with a mass of 1000 kg moving with a speed of 40 km/hr. Determine their momentum. (2.5 marks)

(c) A boy of mass 50 kg was pushed by a constant force of 20 N for 3 seconds. Determine the acceleration acquired by the body. (2.5 marks)

6. John started moving the car from rest and the car accelerated uniformly at the rate of 4 m/s² for 5s and maintained a constant velocity for 20s. Afterwards he applied the brakes and the car retarded uniformly to rest in 3 s. Calculate the total distance covered by the car. (10 marks)

7. (a) Why is an inclined plane regarded as a simple machine? (3 marks)

(b) The wheel and axle with an efficiency of 85 % is used to raise a load of 6000 N. If the radius of the wheel is 50 cm while that of the axle is 15 cm, calculate:

(i) The velocity ratio of the wheel and axle. (3 marks)

(ii) The mechanical advantage of the wheel and axle. (4 marks)

8. (a) Why does a body rotate when a certain force is applied on it? (3 marks)

(b) Figure 1 shows a uniform metre rule or weight 2 N which is pivoted at 40 cm mark. If a force of 4 N acts at the end of the metre rule. calculate the value of force X required to keep the rule in equilibrium. (7 marks)

9. (a) Compare natural gas and geothermal energy sources by considering the following:

1. Environmental salety (2 marks)
2. Sustainability (2 marks)

(b) Using two points, state why solar cars are better than petrol cars (3 marks)

(c) Give three disadvantages of Hydro-electric power (3 marks)

10. (a) Explain how an ammeter and voltmeter are connected in a circuit (marks 6)

(b)  In a circuit shown in Figure 2 below, the battery and an ammeter have a negligible internal resistance . Determine reading of an ammeter. (9 marks)

Figure 2