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THEORY QUESTIONS

WAEC SYLLABUS

1. The time of increase in velocity is called

A. force

B. momentum

C. acceleration

D. speed

2. Which of the following are quantities is a vector?

A. Volume

B. Momentum

C. Energy

D. Speed

3. In an elastic collision, momentum is conserved as well as.

A. velocity

B. kinetic energy

C. potential energy

D. speed

4. The induced current in a coil always flows in a direction so as to oppose the change that causes it. This statement is known as

A Coulomb’s law

B. Lenz’s law

C. Faraday’s law

D. Ampere’s law

5. Which of the following instruments can be used to compare the magnitudes of charges on two given bodies?

A. Electrophorus

B. Ebonite rod

C. Gold-leaf electroscope

D. Proof planes.

ANSWERS

6. A body of mass 2kg is released from a point 100m above the ground. Calculate its kinetic energy 80m from the point of release.

A. 1600J

B. 900J

C.600J

D.200J

7. Which of the following waves is not mechanical?

A. Waves of pipes

B. Water waves.

C. Radio waves

D. Sound waves.

8. A loaded spring is set in simple harmonic motion. The force that tends to restore the load to its equilibrium position is

A. adhesive

B. elastic

C. frictional

D. gravitational

9. Which of the following cases cannot produce total internal reflection? A light ray travelling from

A. glass water

B. kerosene to air

C. air to water

D. water to coerce acting to zero

10. The vacuum in a thermo flask reduces heat loss resulting from

A. radiation only

B. conduction and convection

C. radiation and convention only

D. conduction only.

ANSWERS

11. The diagram above represents an experimental set up for verifying

A. lens formula

B. refraction laws

C. reflection laws

D. miror formula

12 . Which of the following statements about a moving object is correct?

A. When accelerating, the resultant force acting on it must be equal to zero.

B. There must always be non- zero resultant force acting on it

C. At a steady velocity, the resultant force acting on it must be equal to zero.

D. At a steady velocity, the air resistance must be zero

13. If the efficiency of a transformer is 100%,which of the following equations would be correct?

A. NpEp = NsEs

B. NsIp = NpIs

C. NsIs = NpIp

D. IpEs = IsEp

14. A freshly demagnetized bar magnet is placed in the East – West direction to ensure that

A. the molecular magnets remain randomly arranged.

B. the molecular magnetic are properly aligned.

C. it is affected by the earth magnetic field.

D the magnetic domains are within the earth field

15. Which of the following graphs of a charge Q against potential difference V across capacitor is correct ?

ANSWERS

16. A small amount of air is introduced into the vacuum above the mercury in a mercury barometer tube. The mercury level goes down because the air molecules

A. heat the mercury and make it to expand.

B. increases the pressure above the mercury.

C. cools the mercury and make it to contract.

D. decreases the pressure above the mercury.

17. Calculate the quantity of heat needed to change the temperature of 60g of ice at 0⁰C to 80⁰C [Specific latent heat of fusion of ice = 3.36 x 10 ⁵Jkg-1, Specifi8c heat capacity of water = 4.2 x 10³Jkg^-1K^-1]

A. 4.80kJ

B.20.16kJ

C. 40.32kJ

D. 22.17kJ

18. The wire of a platinum resistance thermometer has a resistance of 3.5Ω at 00 and 10.5Ω at 1000C. Calculate the temperature of the wire when its resistance of 7.5Ω

A. 78⁰

B. 25⁰C

C. 36⁰C

D. 57⁰C

19. A transverse pulse of frequency 9Hz travels 4.5m in 0.6s. calculate the temperature of the wavelength of the pulse .

A. 3.33m

B. 0.30m

C. 0.83

D. 1.20

20. In which of the following media is speed of sound the least?

A. Air

B. Brass

C. Water

D. Wood

ANSWERS

23. An 800kg car moving at 80km hr^-1collides with a 1200kg car moving at 40 km hr^-1 in the same direction. If the cars stick together, calculate their common velocity.

A. 60 km hr^-1

B. 8km hr^-1

C. 40km hr^-1

D. 56km hr^-1

24. The mass of a load is doubled while the force acting on its halved. The resulting acceleration of the load is

A. quadrupled.

B. quartered.

C. halved.

D. doubled

25. The maximum and minimum thermometer reads the

A. maximum temperature during the day and the minimum temperature at night at all times.

B. maximum temperature at night and minimum temperature during the day from the last reset

C. maximum temperature at night and minimum temperature during the day at all times.

D. maximum temperature at night and minimum temperature at night from the last reset

ANSWERS

31. Calculate the centripetal force acting on the electron.

A. 7.7 x 10^-47N

B. 6.0 x 10^-8N

C. 3.0 x 10^-14N

D. 5.22 x 10^-26N

32. A device consumes 100W of power when connected to a 120V source. Calculate its resistance.

A. 1.2Ω

B. 12,000.0Ω

C. 20.0Ω

D. 144.0Ω

33. Which property of a wave remains constant when the wave travels from one medium into another?

A. Amplitude

B. Wavelength

C. Velocity

D. Frequency

34. The anomalous expansion of water occur in the range

A. 0⁰C to 100⁰C

B. 0⁰ to 4⁰C

C. 4⁰C to 100⁰C

D. -4⁰C to 0⁰C

35. A ray of light travelling from a rectangular glass block of refractive index 1.5 into air strikes the block at an angle of incidence of 300. Calculate its angle of refraction.

A. 48.6⁰

B. 19.5⁰

C. 20.0⁰

D. 45.0⁰

ANSWERS

36. A rectangle piece of iron measuring 4cm by 3cm at 20⁰C is heated until its temperature increases by 100⁰C. Calculate the new area of the metal. [Linear expansivity of iron is 1.2 x 10^-5K-1]

A. 12.0144cm²

B. 12.0346cm²

C. 12.0288cm²

D. 12.0173cm²

37. Two bodies of masses 3.0kg and 2.0kg are separated by a distance of 50cm. Calculate the force of attraction between them. [G = 6.67 x 10-11 Nm2 kg-2]

A. 1.6 x 10^-9N

B. 1.3 x 10³N

C. 2.3 x 10³

D. 5.0 x 10N

38. The diagram illustrates an object moving in a circular path at constant speed. Which of the arrows indicates the direction of linear velocity?

A. Z

B. X

C. Y

D. W

ANSWERS

41. Which of the following material does not serve as a safety device in electrical circuits?

A. Connecting wires

B. Earth wire

C. Fuse

D. Switch

42. Which of the following liquid has the highest surface tension?

A. Soapy water

B. Cold water

C. Hot water

D. Oily water

43. The nucleon and proton numbers of a neutral atom of an element are 238 and 92 respectively. Determine the number of neutrons in the atom.

A. 119

B. 330

C. 165

D. 146

44. An instrument used to measure relatively humidity is the

A. hygrometer

B. hydrometer

C. pyrometer

D. manometer

45. The area under a velocity – time graph represents.

A. Speed

B. acceleration

C. moment

D. distance

ANSWERS

46. Which of the following statement about a neutral atom is correct? The
A. core is composed of electrons and protons
B number of electrons is equal to that of neutrons.
C. number of neutrons is equal to that of protons
D. number of protons is equal to that of electrons

47. Which of the following properties is not exhibited by sound waves?
A. Diffractive
B. Polarization
C. Interference
D. Reflection

48. When ultraviolet light is incident on certain metallic surfaces, particles are emitted. These particles are called
A. positrons
B. protons
C. photoelectrons
D. photons

49. Niels Bohr drew certain conclusions about the structure of the atom. Which of the following statement is one of those conclusions?
A. The allowed orbits contain the same number of electrons.
B. Within an atom, there are certain allowed orbits.
C. All of the orbits represent the same amount of energy.
D. The orbit with the least energy is farthest from the nucleus.