# WASSCE PHYSICS MAY/JUNE 2012 (SSCE WAEC MAY/JUNE 2012 PHYSICS)

WASSCE PHYSICS MAY/JUNE 2012 (SSCE WAEC MAY/JUNE 2012 PHYSICS)
1

The derived unit of pressure can be expressed as

A. kgms-2

B. kg m-1s-2

C. kg m-2s-2

D. kg m-1s2

2

The diagram above illustrates trapped air in a syringe placed in water that is gradually heated. It is observed that the piston rises as the temperature of the water rises. Which of the following statements explains this observation?

A. frequency of collision of trapped air molecules with walls of the syringe is more

B. molecules of trapped air expands more

C. speed of the trapped air molecules decreases

D. number of molecules of trapped air increases

3. Which of the following devices is used to determine the relative density of an acid?

A. manometer

B. hydrometer

C. hypsometer

D. hygrometer

4. A block of wood of density 0.6 gcm-3, weighing 3.06N in air, floats freely in a liquid of density 0.9 gcm-3. Calculate volume of the portion immersed (g = 10ms-2)

A. 510cm3

B. 340cm3

C. 254cm3

D. 170cm3

5. A metal ball of weight W falls through a column of glycerine of viscosity V. If the ball experiences an upthrust U and terminal velocity is attained is attained, then

A. W > U + V

B. W = U + V

C. W = U - V

D. W < U + V

6. Which of the following substances is the most volatile at room temperature?

A. water

B. diesel

C. petrol

D. kerosine

7. The movement of fluid up or down a narrow tube is

A. osmosis

B. brownian motion

C. capillarity

D. diffusion

8. A bird flies at 10ms-1 for 3s, 15ms-1 for 3s and 20 ms-1 for 4s. Calculate the bird's average speed

A. 4.5 ms-1

B. 15.0 ms-1

C. 15.5 ms-1

D. 51.7 ms-1

9. Which of the following velocity-time graph does not represent an accelerated motion

10. The time of flight for a projectile motion is given by the expression

A. $\frac{U\sin \theta }{g}$

B. $\frac{U\sin \theta }{2g}$

C. $\frac{2U\sin \theta }{g}$

D. $\frac{U\sin 2\theta }{g}$

11. An object is dropped from the top of a tower. If it takes 4s for it to reach the ground, calculate the height of the tower.(g = 10 ms-2, ignore air resistance)

A. 20m

B. 40m

C. 80m

D. 160m

12. When a body is slightly titled, it is found that its centre of gravity s slightly raised. What is the state of equilibrium of the body?

A. unstable

B. stable

C. neutal

D. cannot be detrmined

13. A simple pendulum makes 50 oscillations in one minutes. Determine its period of oscillation

A. 0.04s

B. 0.83s

C. 1.20s

D. 50.00s

14. The tendency for a stationary body to continue to remain at rest when a force is applied to it is known as

A. friction

B. impulse

C. inertia

D. momentum

15. A resultant force of magnitude 15N acts on a body of mass 250g. Calculate the magnitude of the acceleration

A. 0.06 ms-2

B. 3.75ms-2

C. 16.67ms-2

D. 60.00ms-2

16. A girl stands on a scale in a lift. If the reading on the scale is less than her weight, then the lift is moving

A. upward at uniform speed

B. upward with uniform acceleration

C. downward with uniform speed

D. downward with uniform acceleration

17. The S.I unit of heat is

A. joule

B. kelvin

C. watt

D. ampere

18. A body is pulled through a distance of 500m by a force of 20N. If the power developed is 0.4kW, calculate the time for which the force acts

A. 250.0s

B. 25.0s

C. 2.5s

D. 0.5s

19. A metal sheet of area 100cm2 was heated through 70oC. Calculate its new area if the linear expansivity of the metal is 0.000017k-1

A. 100.06 cm2

B. 100.12cm2

C. 100.24cm2

D. 100.36cm2

20. The thermopile is a device for detecting

C. x-rays

D. the presence of electrons

21. In the formation of sea breeze. wind blows from

A. sky to land

B. sea to sky

C. land to sea

D. sea to land

22. A piece of copper of mass 20g at a temperature of 110oC was dropped into a mixture of ice and water at 0oC. If the final steady temperature of the mixture is 0oC . Calculate the amount of ice that melted

[Specific heat capacity of copper = 0.4 Jg-1k-1, specific latent heat of fusion of ice = 330Jg]

A. 0.37g

B. 0.60g

C. 2.40g

D. 2.70g

23. Which of the following factors decreases the rate of evaporation of a liquid?

A. increase in pressure over the liquid

B. lowering the boiling point

C. decreasing in humidity

D. wind

24. When two waves are superimposed on each other, the following occurrences are possible, except

A. nodal lins

B. anti nodal lines

C. stationary waves

D. dispersion

25. Which of the following properties of waves is exclusive to transverse waves?

A. reflection

B. interference

C. diffraction

D. polarization

26. An object of height 2.5cm is places 20cm from a convex mirror of focal length 10cm. Calculate the height of its image

A. 2.5 cm

B. 3.0cm

C. 5.0cm

D. 25.0cm

27. A ray of light passes from glass to air to water to glass to air. Given that the refractive index for light passing from air to water is 4/3 and air to glass is 3/2, calculate the refractive index of glass relative to water

A. 0.50

B. 0.67

C. 0.75

D. 1.13

28. An object is placed at a point X between the focal point F and the optical centre C of a diverging lens. If F is the focal point on the other side of the lens, the image of the object is formed between

A. F and X

B. X and C

C. C and F

D. F and 2F

29. An object is placed 10cm from a converging lens of foal length 15cm. Calculate the magnification of the image formed

A. 3.0

B. 1.5

C. 0.6

D. 0.3

30. A telescope is said to be in normal adjustment when the

A. focal length of he objective is greater than that of the eyepiece

B. focal length of the eyepiece is greater than that of the objective

C. focal length of the eyepiece is equal to that of the objective

D. objective focal point coincides wih that of the eyepiece

31. The sound heard by a person after the reflection of the sound generated by him is called

A. reverberation

B. resonance

C. echo

D. audibility

32. Which of the following sets of coloured light is/are secondary colours

i. Red, Blue and green

ii. Blue, cyan and magneta

iii. Green, Magenta and yellow,

iv.  Yellow, Cyan and Magenta

A. i and ii only

B. ii and iii only

C. iv only

D. i, ii and iv only

33.

34. When two like charges are brought together, the potential energy of the system formed will

A. increase because work is done against the field

B. increase because work is done by the field

C. decrease because work is done by the field

D. decrease because work is done against the field

35. Two capacitors, each of capacitance 2μFμF are connected in parallel. If the p.d across them is 120V, calculate the charge on each capacitor

A. 6.0 x 10-5C

B. 1.2 x 10-4C

C. 2.4 x 10-4C

D. 4.8 x 10-4C

36. Which of the following properties is an advantage of lead-acid accumulator over an alkaline accumulator?

A. possesses low internal resistance

B. can be recharges

C. has shorter life span

D. possesses high e.m.f

37. Six dry cells each of e.m.f. 2.0 and internal resistance of 1.0ΩΩ are connected in parallel across a load of 3.0ΩΩ. Calculate the effective current in the circuit

A. 0.63A

B. 0.50A

C. 0.31A

D. .22A

38

Two similar cells are used to light two similar lamps as illustrated in the diagrams above. In which of the circuit diagrams are the lamps brightest?

A. P

B. Q

C. R

D. S

39. A 120Ω resistor dissipates 8 kJ of heat in 20s. Calculate the current through the resistor

A. 5.8A

B. 6.9A

C. 30.0A

D. 33.3A

40

41. The magnetic relay is a device used for

A. timing in sports

B. storing magnetic field

C. reading the magnitude of magnetic flux

D. controlling another circuit carrying larger current

42. The core of a transformer is usually laminated in order to

A. reduce magnetic leakage

B. reduce eddy current

C. prevent vibration of the transformer

D. make magnetic reversal in the core much easier

43. Which of the following modes is the most economical method of transmitting electrical power over long distances?

A. alternating current at low voltage and high current

B. alternating current at high voltage and high current

C. alternating current at high voltage and low current

D. direct current at low voltage and high current

44. An inductor is connected to a 24V, 50Hz mains supply. If the current through the inductor is 1.5A, calculate the inductance of the inductor (π=22/7)

A. 8.0 x 102H

B. 7.5 x 10oH

C. 1.6 x 10oH

D. 5.1 x 10-2H

45. In a R-C circuit

A. Irms leads Vrms by 60o

B. Irms slags Vrms by 60o

C. Vrms lags Irms by 90o

D. Vrms leads Irms by 90o

46. An atom in an excited state is one whose

A. potential energy is minimum

B. potential energy is maximum

C. electron are in the conduction band

D. electron have moved to higher energy level

47. A metal with a work function of 3.0ev is irradiated with ultraviolet light of energy 4.0 ev. The kinetic energy of the ejected electron is

A. 1.0eV

B. 3.0eV

C. 4.0eV

D. 7.0eV

48. Which of the following statements about X-rays is correct? X-rays

A. are produced when a metal surface is irradiated with ultraviolet light

B. are produced when a metal target is used to block fast moving electrons

C. have long wavelengths and are therefore very penetrating

D. are not part of the electromagnetic spectrum

49. Which of the following arrangements of radiations is in the order of decreasing penetrating power?

A. α, β, γ

B. α,γ, β

C. γ, β, α

D. β, γ, α

50. Which of the following radiations emitted in radioactive decay has momentum, a fairly high penetrating power and is deflected by a magnet?

A. alpha particles

B. beta particle