UNEB UCE PHYSICS PAPER 1 Nov./Dec. 2005

SECTION A : (40 MARKS )

Answer all questions in this section.

(2005 Q.1).  When a car is suddenly brought to rest, a passenger jerks forward because of

A. inertia.  B. friction.

C. gravity,  D. momentum.

(2005 Q.2). The direction of induced current in a conductor moving in a magnetic field can be predicted by applying

A. Faraday’s law.

B. Maxwell’s screw rule.

C. Fleming’s left hand rule.

D. Fleming’s right hand rule.

(2005 Q.3, The mode of transfer of heat between the boiler and the storage tank of a hot water supply system is

A. radiation. B. conduction,

C convention. D, evaporation,

(2005 Q.4). A rectangular block of tin is 0.5 m long and 0.01 m thick. Find the width of the block if its mass and density are 0 45 .kg and 9000 kg m”” respectively.

A- 0.005 x 0.45 x 9000 m  B. 0.45 __–__ 9000 x 0.005

C.  D.m

____ 0.45 x 9000

9000

(2005 Q.5). A charged conductor usually loses charge gradually by a process called

A.  induction. B. insulation.

C. conduction. D. ‘leakage.

(2005 Q.6). In a four-stroke combustion engine, the correct order of strokes is

A, compression—–> power—–^.e/.naust—–*> induction. _…._

B. exhaust —–^ compression—–^ power -—> induction. I

C. induction—–^ compression—–& power _>. exhaust, j

D, induction -—^ power -—^ compression—–&> exhaust.

(2005 Q.7) A cork held under -water rises to the surface when released because the upthrust on it is

A. greater than the weight.

B. less than the weight.

C. equal to the weight.

D. equal to the weight of water displaced.

.1.5V.P

(2005 Q.10), A body moves with uniform acceleration if

A. its momentum remains constant.

B. it covers equal distances in equal times.

C. the velocity changes by equal amount in equal times.

D. the net force on the body is zero.

A cell of e.m.f 1.5 V and internal resistance,’n is connected in series with a 5 .Q resistor as-shown in Figure 1. If the current in the circuit is 0.25 A, find r.

A. 1Q. .._:

B. 60.

c, na

D. 16 Q.

(2005 Q.9). The width of a metre rule is accurately measured by a

A. micrometer screw gauge. B. vernier cahper.

C. tape measure,  D. metre rule.

(2005 Q.11).
Which one of the following statements is true when a stone of mass 2 kg and that of 1 kg are released from the same point at the same time?

A. Both masses will hit the ground al the same time.

B. The 2 kg mass will hit the ground first.

C. The ! kg mass will hit the ground first.

D. They fall with different speeds,

(2005 Q.12). Force is given by the product of

A. displacement and velocity.  B. displacement and mass.

C. acceleration and mass, D. velocity and mass.

13. A cyclist travelling at a constant acceleration of 2 ms~~ passes through two points A and B in a straight line. If the speed at A is 10 ms”¹ and the points are 75 in apart, find the speed at B.

A. B.

C. D.

15,8 ms”^! 17.3ms”¹ 20.0 ms”¹ 4QQ.O ms

14. A vibrator produces a sound wave that travels 900 rn in 3s. If the wavelength of the wave is 10 nt_v find the frequency of the vibrator.

A. 30 Hz

B. 270 Hz

C. 300 Hz

D. 3000 Hz.

(2005 Q.15). The distance between the fixed points on a mercury in glass thermometer is 25 cm. What is the temperature in degrees celcius if the mercury thread is 8 cm long ?

A.

B.

D.

25

25jL§ 300

25 x 8

16.

(2005 Q.17).

A solid, Q, sinks deeper in liquid, N, than in liquid, M, because the

A. upthrusi on the solid is greater in liquid N than in M.

B. density of liquid M is greater than that of N

C. density of liquid N is greater than that of M,

D. surface tension of liquid N is less than that of M.

A. ^B–

5.0x 10° 5.0 x 10¹ 5.0 x 10²

5.0 x 10⁴

J

18.

20.

A radioisotope of sodium atom decays by emission of a beta particle as shown in the equation above. Find the values of A and 2.

A. B, C. D.

24 24 24 24

Z

10 11 12 13

(2005 Q.19). The strength of a material depends on the

nature of the material, iiiumetei of the material, length of the material.

21.

Figure 2 shows a wave produced in a siring. If the frequency is 2 Hz. ai what speed do the waves travel along the string ?

A. 0.5 ms~

B, I.Oms”
‘ C.

D. 4.0

Effort

(2005 Q.22).  Fig. 3

What is the velocity ratio of the pulley system shown in Figure 3 ?

A. 1

B. 2

C. 3

n. 4

(2005 Q.23).  When a crystal of polassiur _t rnanganate is carefully placed at the bottom of a beaker containing wruci rt spreads uniformly in the water after some da\s due lo

{.’.
S’lrfllCC tension.

1). Brov\nian motion.

L

23. TV . e’ronuL’netic radiation which causes the body temperature to rise is

called
^
*

\-rays.

o. .gamma rays. C. infra red. H. ultra violet.

24.

: ao

~A

Time/s

Fig.

Figure 4 shows a graph tif the temperature rise \\\->\ :;:;,, \-..\.\\.< mass 4 kg is healed using a 2UOO W healer. I’md us -^x ,;!i, he •( in Jkg~’ K”¹.

A- _40_xJll_

2000 x 4

B.

C. D.

40 \ 10

40 x 4

25.  Power loss Line to cdd\ em-rents in the core of a transfonnei ::;;i be minimised by

A, laminating the core.

B. using thick copper wires in the windings. (“. using a soft iron cure.

D. Vvinding the secondary coil on top of the pnmin vc.’!

26.  Soup !•••• used to wash clothes because it

A. increases capillarity in the clothes.

B. reduces capillarity in the clothes.

C. increases surface tension allowing waior to pei¹. • ‘.• the dirt easily.

1). reduces surface tension allowing water to peiv.•*._: j\. \”•.••.

dirt easih.

27.  Hgiue 5- shows a uniform beam in equilibrium when a force R acts on it at one end. Find the weight, W₇ of the beam.

X R/

C.

D.

RX

ex

28.  

A brass rod is rubbed with silk and then brought near a positively charged gold leaf electroscope. The divergence of the leaf will

A, B. C.

D.

increase,

decrease,

not change.

increase slightly and fall back.

(2005 Q29.).  A concave mirror can be used as a shaving mirror because when an object is placed between the focus and the pole, the image formed is

magnified, virtual and erect. magnified, real and inverted. diminished, real and inverted. diminished, virtual and erect.

D.

40 N

50 N

30.  Fo’ces of 60N, ION. 40N and ION act on a body as shown in Figure 6. hi which direction does the body move?

Upwards. IViwn wards. To iS«c left. To the rieht.

31.  A run-en! of IOA flows through an electric heater for 1 h. If 7,2 x 10⁶ J of ciect.MCji L-zKTgv is converted to heat, find the n.d. across the heater.

32. A mass of 0.2 kg produces an extension of X cm in a spring. required to produce an extension of 6 cm is

A. 0.75 N.

B. 1.50 N.

C. 2.70 N.

D. 24.00 N.

33.

Electron beam

Fig. 7

Figure 7 shows a beam ot electrons incident mid way between iwo charged metal plates. Which of the following is correct 7 The beam

A. is deflected towards the positive platd
,———-

B. is deflected towards the negative plate.
I
[

C. moves perpendicular to the plates.
[
j

D. passes through the plates undetected.

34. The result of rubbing a glass rod with silk and separating them is

A. a negative charge on the rod and an equal positive charge

on the silk.
______^

B. equal amounts of negative charge on both.

\

C. a positive charge on the rod and an equal negative charge ) on the silk,

D. no charge on both the rod and the silk.

35. If the cost of one unit of electrical energy is Sh. 150, find the o>si ^ •* v.:’£ two 75 W lamps for 2 hour*

A. Sh.0.30
“……..^!

B. Sh.4.00
‘

C. Sh.22;50
^l–………

D. Sh4500

36. The half life of a radioactive element is 2 minutes What fraction of ‘ : initial mass is left after B minutes?

A. V_:  B. C. V_s D. ‘<",

(2005 Q.37). Lidt; energy is reflected when,

A. angle of incidence is greater than angle of reflection.

B. angle of incidence is equal to ancle of refraction,

C. angle of incidence is equal to i;m::’!v- of reflection.

D. the normal at the point of incidence iviakey the same angle us the

 incident ray.

38. [n a dry ceil, manganese (IV) oxide is used to

A. reduce (he p.d. across it.

B. double its resistance.

C. increase its resistance.

D. keep the p.d.. constant.

39. A longitudinal wave is one in which the

A. direction of propagation is parallel to that of the vibration

producing it.

particles of the medium through which it travels move

opposite to the direction of propagation.

direction of propagation is perpendicular to that of the

vibration producing it, D. particles of the medium through which it travels move

together with it.

(2005 Q.40).  an object is placed 30 cm in front of a plane mirror. If the mirror is moved a distance o! 6 cm towards the obicct. Find the distance between ihe object and

its image.

A. 24cm

B. 36 oh

C. 48 cm

D. CO cm

41.

SECTION B : (40 MARKS)

Answer all the questions in this section.

Fig. 3

Figure 8 shows a ray of light incident on a semi-circular glass block af centre C.

(a) Why is the ray not deviated ?

(b) Calculate the value of angle 8 if the refractive index of glass Is 1S2.

42, (a) What is meant by mass of a body ?

(Of

(b) (i) A body whose weight in air is 52N experiences an upTrirjst of 12 N in a fluid. Find its apparent weight.
(t72 mar**

(ii) What happens to the weight of the txxiy at a much higher

altitude?
(01 mart)

11

43. (a) Sketch a p.d versus current graph for an ohmic resistor. (01 mark)

45, (a) Define a joule.

(b) State one example of a non-ohmic conductor.

(01 mark:

(c) Find the voltage across a 3 Q resistor if a current of 4A passes through

(02 marks)

I

it.

(b) A boy of mass 45 kg runs up a flight of 60 steps. If each step is

12 cm, find the work done against gravity by the boy. (03 ?;’.v«r£/J

44. (a) State.Boyle’s law.

46. (a) What is a soft magnetic material 1

‘b) State two ways in which a bar magnet enrobe demagnetised.

(b) A volume of a fixed mass of a gas increases from 300 err/ to 500 , at a conMani temperature. Find the nc\v pressure if the initial press. is 70 cm Mil.

12

(c)

Conductor carrying current

Fig. 9

Figure 0 shows a straight conductor carrying current between :he pol of a permanent magnet. Sketch on the diagram above the res meant magnetic field pattern.

(02 mwk:\ Turn O>er

47, (a)

copper

–^iron

Fig. 10

Figure 10 shows strips of copper and iron bonded together.

(i) Redraw the diagram to show what happens when the strip is heated.
(01 mark)

_(ll}
Why does the change you have shown in (a) (i) take place ?

(01 mark)

_(b) Why is the freeze compartment of a ref ngerator placed at the top ?

(02 marks)

48,

P Q

Fig. 11

14

(a) Figure 11 shows the main parts of a cathode ray oscilloscope.

Name the parts labelled P, Q, R and T.
(O?/;.Y//-v.v)

P

Q R T

(b) Slate the functions of parts labelled Q and T.

Q

49. (a) Distinguish between cohesion and adhesion.

(b) Sketch diagrams 10 show the level of liquid in a capillary lube that is immersed in a liquid which has greater:

U) cohesion than adhesion

15

(ii) adhesion than cohesion
(01 mark)

50. (a) What is an echo ?
(01 mark)

(b) An echo sounder on a boat sends down a pulse through the water and receives its echo 0.9 s later. If the velocity of sound in the water is 1450 ms~\ calculate the water depth,
(02marks)

(c) State any two factors which determine the frequency of a note

produced when a guitar string vibrates.
(01 mark)

END 16