🌊PAPER 03-QNS

 

THE UNITED REPUBLIC OF TANZANIA

PRESIDENT’S OFFICE

REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

FRANCISCAN GIRLS SECONDARY SCHOOL

FORM FOUR PRE NATIONAL EXAMINATION

031/1 PHYSICS 1

(For Both School and Private Candidates)

Time: 3 Hours Friday 25^th October 2024

Instructions

1. This paper consists 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. Communication devices and any unauthorized materials are not allowed in the examination room.

4. Non-programmable calculator and mathematical tables may be used.

5. Write your Examination number on every page of your answer sheet (s) provided.

6. Where necessary the following constants may be used:

1. Acceleration due to gravity, g=10m/s².

2. Pie, 𝜋 = 3.14.

3. Specific heat capacity of water = 4200 J/kgK

4. Velocity of sound in air, v = 340 m/s.

SECTION A (16 Marks)

Answer all questions in this section.

1. For each of the item (i) - (x), choose the correct answer from among the given alternatives and write its letter beside the item number in the answer sheet provided. (10 marks)

(i) Which of the following scientific procedure statements needs to be proved through scientific research ?

A. Hypothesis B. Principle C. Measurement D. Proposal E. Conclusion

(ii) Which of the following statements 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) Archimede’s principle can be used to support or deduce the following statements;

1. A vacuum is needed at a top of a barometer

2. Hydrometer have narrow stems to make them more sensitive

3. The relative density of a solid is the ratio of the weight in air to the apparent loss in weight in air.

Decide which of the following responses is (are) correct ?

A. 1, 2 and 3 B. 1, 2 only C. 2, 3 only D. 1 only E. 3 only

4. The figure 1 shows roughly the different parts of the electromagnetic spectrum.

Which of A, B, C, D and E represents the x-ray section?

A

B

C

VISIBLE LIGHT

D

E

 Figure 1

4. A ball of mass 0.5 kg, released from a height of 20 m above the ground, rebounds to a height of 5 m. If the ball is in contact with the ground for 0.1 sec, the loss of energy due to impact is

A. 5 J B. 10 J C. 25 J D. 50 J E. 75 J

(vi) A nucleus of an element Q which is ²⁰²₈₄𝑄 emits 𝛼− particle and 𝛽− particle. The final nucleus formed has an atomic number of

A. 83 B. 82 C. 198 D. 200 E. 80

(vii) In figure 2, X and Y are two parallel soft iron rods inside a solenoid S. When a high current flows in S, then X and Y

Figure 2

1. Stay still

2. Attract each oher

3. Move to the right

4. Move to the left

5. Repel each other

(viii) Colours are produced when white light passes through a glass prism because

1. The light waves interfere

2. The glass colours the light

3. Different colours travel at different speed in glass

4. The different colours are filtered

5. Diffracton of light occurs

9. Which of the following resources of energy is non-renewble ?

A. Ocean waves B. Water C. Solar radiation D. Wind E. Fossil fuel

9. Which of the following is an example of a scalar quantity ?

A. Electric current B. Force C. Velocity D. Displacement

E. Acceleration

2. Match the different positions of the object placed infront of a concave mirror as shown in list A with their corresponding image positions in List B by writing the letter of the correct response beside the item number in the answer sheet provided.

(6 marks)

KEY

C = Centre of curvature of the mirror

F = Principal focus of the mirror

P = Pole of the mirror

List A (Object positions)	List B (Image positions)
Beyond C At C Between F and C At F Between F and P At infinity	Behind the mirror At C No image formed At F At infinity Between C and F Beyond C At P

SECTION B (54 Marks)

Answer all questions in this section

3. (a) With the aid of a sketched graph, explain how angle of incidence affect angle of deviation in a triangular glass prism (3marks)

2. A partient’s eye can focus only on objects beyond 100 cm. What word characterizes this type of vision problem ? What are the focal length and power of contact lens needed to correct this problem ? (6 marks)

4. (a) A hydraulic press has pistons with areas of 0.02 m² and 0.1 m² as shown in figure 3. A car weighing 5000 N sits on a platform mounted on the larger piston. How far must piston 1 be pushed downward to raise the car 0.3 m ? (5 marks)

Figure 3

2. Why luggage compartments are located at the bottom of a bus ? (4 marks)

5. (a) Explain why action and reaction forces never cancel each other ? and Provide three examples which illustrate the application of the law of conservation of linear momentum (4 marks)

2. Sir mlangi was driving on a rough road. The right front tyre of the car ran over a sharp object and got a puncture. He used a screw-jack with a handle which has a length of 40 cm long and a pitch of 0.5 cm to lift a car whose mass is 350 kg. If the efficiency of the screw-jack is 45%, calculate the amount of force applied at the end of the handle when lifting the car. (5 marks)

6. (a) The hot water tap of a bath delivers water at 80℃ at rate of 10 kg/min. The cold water tape of the bath delivers water at 20℃ at a rate of 20 kg/min. Assuming that both taps are left on for 3 minutes, calculate the final temperature of the bath water, ignoring heat losses (4 marks)

2. Heat energy may be transferred from one body to another by convection, conduction and radiation. Describe how the heat energy is transferred and how to minimize heat loss in each case (5 marks)

7. (a) Describe how length, tension and mass per unit length affect the frequency of the vibrating string. (5 Marks)

2. Explain the behaviour of gamma radiation, alpha and beta particles with respect to electromagnetic fields (4 marks)

1. (a) What hazards are associated with earthquakes ? (4 marks)

   2. Briefly explain how tides are formed and and why they are so important? (5 marks)

SECTION C (30 Marks)

Answer two (2) questions from this section

9. (a) Explain why a check against short circuit should be made when using secondary cells such as lead plate accumulators, whereas this is not so important when dry cells are used (3.5 marks)

2. Two heating coils dissipate heat at the rate of 40 W and 60 W respectively when connected in parallel to a 12 V d.c supply of negligible internal resistance.

1. Calculate the resistances of the coils. (3.5 marks)

2. Assuming that these resisances remain constant, what would be their rates of dissipation of heat when connected together in series with the same power

supply as before ? (3.5 marks)

2. Compare the behaviour of Cathode rays and X-rays when subjected to both magnetic and electric fields.(4.5 marks)

10. (a) The detection of nuclear radiation is based on its ionising effects, different detectors are designed using different technologies for detecting different types of nuclear radiation and one of the detector is Geiger-Muller counter, With the aid of a labelled diagram explain how Geiger-Muller counter is used to detect nuclear radiations (5 marks)

((b) Describe 𝑝−𝑛 juction diode characteristics and sketch a graph to show how the current through it varries with potential difference (p.d) across it (5 marks)

(c) With the help of sketch, state how full wave rectification can be archieved using only two diodes (5 marks)

11. (a) Why the frequency of the fundamental may alter during the day ? A pipe closed at one end has a length of 10 cm. calculate the frequency of the fundamental and the first overtone (6 marks)

2. In Tanzania, electricity is distributed throughout the country by the National Grid System which transmits a.c at a very high voltages. Explain

1. Why is it necessary to step up the voltage it up before transmission in the grid ? (2 mark)

2. What will happen if direct current is to be used instead of alternating current. (1 mark)

(iii) What will happen if large current is to be used instead of the high voltage. (1 mark)

(c) Figure 4 shows a solenoid connected to a galvanometer.

Figure 4

Explain why

1. If the magnet is held stationary at the end of the coil, there is no deflection of the galvanometer pointer (1 mark)

2. If the magnet is moved towards the solenoid there is a deflection of the galvanometer pointer (1 mark)

3. The faster the magnet moves towards the solenoid the greater is the deflection of the galvanometer pointer (1.5 mark)

4. If the magnet is moved away from the solenoid the direction of the current is from A to B through the galvanometer (1.5 mark)

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