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## 2¼ hours

UGANDA NATIONAL EXAMINATION BOARD

Uganda Certificate of Education

PHYSICS

Paper 1

Time: 2¼ hours

SECTION A (40 MARKS)

Answer all questions in This section.

1.  Which of the following shows the correct stages in an internal combustion engine?

A.  Compression ®Power®Exhaust ® Induction

B.  Exhaust ®Induction ®compression ®Exhaust

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C.  Induction ®Power®compression ® Exhaust

D.  Induction ®Compression®power®Exhaust

2.  The product of mass and acceleration is

A.  force.

B.  inertia

C.  velocity,

D.  momentum

3.  A dull black surface is a good

(i)  absorber of heat energy,

(ii)  emitter of heat energy.

(iii)  reflector of heat energy.

A.  (i) only.

B.  (i) and (ii) only.

C.  (ii) and (iii) only

D.  (i), (ii) and (iii)

4.  Calculate the efficiency of the pulley system shown in Figure 1 if the minimum effort needed to raise a load of 210 N is 90N.

A.

B.

C.

D.

5.  Turbulent flow of a fluid in a pipe may be caused by

(i)  making the pipe narrow.

(ii)  laying the pipe steeply.

(iii)  making the fluid to flow slowly and uniformly.

A.  (i) only,

B.  (i) and (ii) only,

C.  (ii) and (iii) only,

D.  (i), (ii) and (iii).

6.  When an inflated balloon is released in air with its neck opened, it will

A.  rise up.

B.  drop to the ground instantly.

C.  move in the opposite
direction to the escaping air,

D.  remain in one position

7.  A crane lifts 4 bricks per minute through a height of 1.5 m. Find the power that is expended if each brick weighs 100 N,

A.  2.5 W.

B.  10.0 W.

C.  150.0 W.

D.  600.0 W.

8.  A force of 20 N extends a spring by 10 mm. Find the extension, in mm, caused by a mass of 0.5 kg.

A.   0.25

B. 1.00

C.   2.50

D.  10.00.

9.  The ticker-timer tapes below show the motion of four trolleys moving from left to right. Which one of them is accelerating ?

Direction of motion

10.  A piece of metal of mass 120 g is placed in a 100 ml measuring cylinder containing 20 ml of water. Find the density of the metal if the water level rises to the 50 mi mark.

A. 12 gcm-3.

B. 2.4 gcm-3.

C
4.0 gcm-3.

D.
6.0 gcm-3..

11.

Fig. 2

Figure 2 shows a block of wood of volume 40 cm3 floating in water with only half of its volume submerged. If the density of water is 1000 kgm-3 , determine the mass of the wood under water.

A.  40 x 1000 kg.

B.  20 x 1000 kg,

C  40 x l0-6 x 500kg.

D.  20 x 10-6 x 500 kg.

12.  Surface tension in a liquid may be weakened by

A.  lowering the temperature.

C.  increasing the amount of liquid.

D.  increasing the density of the liquid.

13.

A heater rated 6000 J/min is placed in 2 kg of a liquid. The temperature rise varies with time as shown in Figure 3. The specific heat capacity of the liquid in J kg-1 K-l is

C.

D.

14.  A magnet can be made to lose its strength by

(i) heating

(ii) throwing it violently.

(iii) putting it in a solenoid carrying direct current

A.  (i) and (iii) only,

B.  (ii) and (iii) only,

C.  (i) and (ii) only,

D.  (i), (ii) and (iii).

15.  A given mass of gas occupies a volume of 200 cm3 at a temperature of 27 C and a pressure of one atmosphere. Find the volume when its temperature

rises to 54 C at constant pressure,

A.

B.

C.

D.

16.  A material that can be rolled into sheets or drawn into wires without breaking is said to be

A.  strong.

B.  elastic.

C.  ductile.

D.  brittle.

17.  Radiation is the transfer of heat

A. in a liquid which involves the movement of the molecules.

B. from
one place to another by means of electromagnetic waves.

C. through a material medium without the bulk movement of the medium.

D. through a fluid which involves the bulk movement of the fluid itself.

18.

A light beam AB is in equilibrium when forces of 2N, 2N and P act as it as shown in Figure 4. Find the magnitude of P.

A.  5N

B.  4N

C.  2N

D.  1N,

19.  When potassium dichromate dissolves at die bottom of a water container, it spreads slowly throughout water by a process called

A.  evaporation.

B.  diffusion,

C.  capillarity,

D.  convection.

20. The basic difference between transverse and longitudinal waves is in

A. amplitude.

B. wavelength,

C. direction of vibration.

D.  medium through which the waves travel,

21.
A nickel nuclide, , contains

A. 28 protons and 28 neutrons.

B. 32 electrons and 28 neutrons.

C. 28 protons and 32 neutrons.

D. 28 electrons and 32 protons.

22. In a ripple tank, constructive interference occurs when

A. the wave is stationary.

B. a crest overlaps with a trough.

C. a crest overlaps with a crest.

D. the wave strikes a barrier,

23. The activity of a radioactive element with a half life of 30 days is 2400 counts per second.

Find the activity of the element after !20 days.

A.   75 counts per second.

B.  150 counts per second.

C.  300 counts per second.

D.  600 counts per second.

24.

When a current, I, flows through a wire placed in between the poles of a U-magnet as shown in Figure 5, the wire will move

A.  upwards.

B.  downwards.

C.  towards the south pole.

D.  towards the north pole.

25.

Fig. 6

Five forces of 5N, 3N, 4N, 3N and 3N act on a body as shown in Figure 6. Find the resultant force on the body.

A. 2N

B. 7N

C. 12N

D. 18N.

26.

Fig. 7

Figure 7 shows white light incident on a magenta colour filter. What colour filter should X be so that red is seen on the screen?

A. Cyan

B. Blue

C Black

D. Yellow

27.  An object 6 cm high is placed 24 cm from a tiny hole in a pin-hole camera. If the distance from the hole to the
screen is 8 cm, find the size of the image on the screen.

A.   0.2cm.

B.   2.0cm.

C.  18.0cm.

D.  32.0cm.

28.  Two appliances rated 240 V, 2 KW and 240 V, 500 W. Find the cost of running these appliances for three hours if one unit of electricity costs Shs. 70.

A.  Shs. 105

B.  Shs. 175

C.  Shs. 420

D.  Shs. 525

29.  When does the eclipse of the moon occur?

A.  When the moon is between the sun and the earth

B.  When the earth is between the sun and the moon

C.  When the sun is totally eclipsed by the moon

D.  When a bright ring of sun light shows round the age of the moon

30.

Figure 8 represents straight waves, A, B, C, D, E and F. if after 5s A occupies the position now occupied by F, find the wave length of the wave.

A.  1 Hz

B.  3 Hz

C.  9 Hz

D.  15 Hz

31.  Which one of the following bands has a wave length greater than that of visible spectrum.

A.  Gamma

B.  X-rays

C.  Ultra-violet

D.  Infrared

32.  A body of mass 2kg initially moving with a constant velocity of 10 ms-1 is subjected to a force of 5 N for 5s. the change in momentum of the body in kgms-1 is

A.  10

B.  20

C.  30

D.  50

33. When a charged body is brought near a cap of a negatively charged gold leaf electroscope, (he

A.  divergence of the leaf does not change.

B.  leaf falls if the body is negatively charged.

C  leaf diverges if the body is positively charged.

D.  leaf diverges if the body is negatively charged.

34.  A straight line through the origin of a velocity-time graph shows that the

A. velocity is uniform.

B. distance is increasing uniformly.

C. acceleration is uniform.

D. motion is retardation.

35.  How long does it take an alternating p.d. of peak value 10 V and frequency 50 Hz to make one cycle?

A. 0.02s.

B. 0.20 s.

C. 5.00s.

D. 500.00s.

36.  An electric bulb has a resistance of 960W. Find the electrical power expended when connected across a 240 V supply.

A.

B.

37.  Which one of the following materials can be electrified by friction?

A. Plastic pen.

B. Silver rod.

C. Copper rod.

D. Wet wood.

38.  A p.d of 20 V is applied across two resistors of 4 Q and 6 Q, connected in series. Determine the p.d. across the 6 £2 resistor if the total circuit current is

A.  1.0 V,

B.  2.0 V.

C.  3.3V.

D.  12.0V

39.  Which of the following statements is/are true ?

(i) When identical cells are in parallel, Ihe total e.nLf is the sum of individual e.mjfs.

(ii) In a lead-acid accumulator, the lead peroxide acts as the positive pole.

(iii) Use emf of a ceil is the total p,d. across the external ami internal resistances.

A.  (i) only.

B.  (i) and (ii) only.

C.  (ii) and (iii) only.

D.  (i), (ii) and (iii) only.

40.  When a steadily increasing force is applied to a moving object, all the following change except

A.  acceleration.

B.  momentum.

C.  speed.

D.  mass.

SECTION B (40 MARKS)

Answer all questions in this section. All working must be shown in the spaces provided,

41.  (a)  State two reasons why mercury is preferred to alcohol as a thermometric liquid.  (02 marks)

(b)  In a gas thermometer, the pressure of the gas at 0 °C is 20 cmHg and at 100 °C is 27cmHg. Determine the room temperature if the pressure at this temperature is 21.4 cmHg.  (02 marks)

42,  (a)  What is an echo ? (01 mark)

(b)  When a hunter fires a gun, an echo from a cliff is heard 8 s later. How far is the hunter from the cliff ? (Speed of sound = 340 ms-1).

(c)  State one practical application of echoes. (01 mart)

43.  (a)  Name the particles emitted by radioactive materials.  (02 marks)

The path of one of the particles in (a) through a magnetic field is as shown in Figure 9.

44.  (a)  What is meant by uniform velocity ?  (01 marts)

(b)  A car travelling with a uniform velocity of 25 ms”! for 5s brakes and then comes to rest under a uniform deceleration in 8 s.

(i)  Sketch a velocity-time graph of the motion,  (01 mark)

(ii)  Find the total distance travelled. (02 marks)

45.

Figure 10

Figure 10 shows a negatively charged ball, B, inside & hollow metal conductor, resting on an insulator. Describe the distribution of charge on the metal conductor:

(i)  before B touches P. (02 marks)

(ii)  after B touches P. (02 marks)

46  (a)  Define the term lateral inversion as applied to mirrors. (01 marks)

(b)  State two properties of an image formed in a concave mirror when the object is placed between the focal point and the mirror. (01 marks)

(c)  Sketch arty diagram to show how refraction of light makes a pool to appear shallower than its actually is.   (02 marks)

47.  (a)  Define the joule. (02 marks)

(b)  The work done to move a body through a distance of 5m is 30J. Find the force that acts on the body. (03 marks)

48.

Fig. 11

A coil is wound on a soft iron rod as shown in Figure 11.

(a)  Describe what is observed when the key, K, is

(i) closed.  (01 mark)

(ii) closed and then again opened.  (01 mark)

(b) State two ways by which ihe effect of what was observed in (a) (i) above can be increased.

(02 marks)

49.

Fig. 12

Figure 12 shows the main features of a cathode ray oscilloscope (C,R O.).

(a)  (i)  Name the parts labelled A, B and C. (1½marks)

a .   ……,.;……………………………

B.  …………………………………..

C.  …………………………………..

(ii)  State the function of the part labelled B.  (01 marks)

(b)  State three applications of a C.R.O.  (1½marks)

50.

Fig, 13

Figure 13 shows a frame work of girders. Identify any two girders which are in

(i)  tension (02 marks)

(ii)  compression  (02 marks)

END

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