Physics 2020 Past Question | WAEC
- In collision between two objects, kinetic energy is conserved only if
- A. one of the objects was initially at rest
- B. potential energy is converted to work
- C. the collision is inelastic
- D. the collision is elastic
2. The quantity of motion of a body is its
- A. acceleration
- B. displacement
- C. momentum
- D. velocity
3. The volume of a fixed mass of a gas varies inversely as the pressure on it provided the temperature is constant. This statement is
- A. Pressure law
- B. Charles law
- C. Boyle’s law
- D. General gas law
4. An image formed on a screen is always
- A. inverted
- B. magnified
- C. upright
- C. virtual
5. How would the capacitance of a parallel plate capacitor be affected if the distance of separation of its plates is decreased? It will
- A. increase in value
- B. decrease slightly
- C. remains unchanged
- D. drop to zero
6. Which of the following machines does not apply the lever principle?
- A. Claw hammer
- B. Wheelbarrow
- C. Single pulley
- D. sugar tong
7. The average distance moved by a molecule between collisions is called
- A. molecular distance
- B. intermolecular distance
- C. mean distance
- D. mean free path
8. Which of the following waves requires a material medium for its propagation?
- A. Radio waves
- B. Light waves
- C. Sound waves
- D. X-rays
9. The depolarising agent in a Leclanche cell is?
- A. carbon rod
- B. ammonium chloride
- C. manganese (IV) oxide
- D. zinc plate
10. The material used to slow down the neutrons in a nuclear reactor is
- A. boron
- B. copper
- C. graphite
- D. uranium
11. Which of the following statements explain why hot soapy water is more effective in cleaning oil-stained dishes?
- A. The oil on the dishes repels the soap
- B. soap and heat decrease the surface tension of oil
- C. soap increases the surface tension of oil and water
- D. Hot water increases the surface tension of oil
12. The diagram above illustrates a beam of parallel rays from a distant object O, incident on one side of the total reflecting prism. Which diagram does not represent the correct path of the beam when it emerges from the prism?
- A. W
- B. X
- C. Y
- D. Z
13. An electrical device has 50 turns in its primary coil be an
- A. step-up transformer
- B. step-down transformer
- C. d.c generator
- D. a.c generator
14. The earpiece of a telephone handset converts energy from
- A. electrical to sound
- B. sound to electrical
- C. sound to electrical
- D. sound to radio wave
15. Two identical cups containing the same volume of water at 45°C and 5°C, are left in a room at 25°C. Which of the following graphs correctly illustrates the variation of temperature with time?
- A. A
- B. B
- C. C
- D. D
