Waec 1992 Physics Past Questions And Answers
The angle of deviation of light of various colours passing through a glass prism decreases in the order of
- A. blue orange and red
- B. red, blue and orange
- C. blue, red and orange
- D. red, orange and blue
In a domestic circuit, electrical appliances and lamps are arranged in parallel across the mains so as to enable the
- A. same current to flow through the electrical appliances and the lamps
- B. maximum energy to be consumed at least cost
- C. same fuse to be used for the electrical appliances and the lamps
- D. voltage across the appliances not to be affected when the lamps are switched on and off
The change of the direction of a wavefront as a result of a change in the velocity of the wave in another medium is called
- A. refraction
- B. reflection
- C. diffraction
- D. polarization
A pipe closed at one end is 1.0m long. The air in the pipe is set into vibration and a fundamental note of frequency 85Hz is produced. Calculate the velocity of sound in the air. (Neglect end correction).
- A. 340.0ms-1
- B. 33Oms-1
- C. 170ms-1
- D. 85.0ms-1
What change in velocity would be produced on a body of mass 4kg if a constant force of 16 N acts on it for2 s?
- A. 0.5 ms-1
- B. 2.0ms-1
- C. 8.0 ms-1
- D. 32.0 ms-1
Which of the following radiations have the highest frequency?
- A. Radio waves
- B. Light waves
- C. X-rays
- D. infra-red rays
(a)(i) What is meant by resonance?
(ii) Outline the necessary steps taken in a simple experiment to illustrate top resonance
(iii) Explain why a vibrating tuning fork sounds louder when its stem is pressed against a table top than when held in air.
(b) Explain with the aid of diagrams, how a concave mirror could be used to: (i) Ignite a piece of carbon paper; (ii) produce an exact copy of a picture on a screen.
Which of the following waves are longitudinal waves? l. Ripples on the surface of water II. Waves produced by a tuning fork vibrating in air III. Light waves IV. Waves produced by a flute
- A. I and II only
- B. I and III only
- C. II and III only
- D. II and IV only
As an object is moved close to the focus of a converging lens from infinity its image I. moves closer to the lens II. moves away from the lens. III. Remains the same size. IV becomes smaller. Which of the statements above is/are correct?
- A. III and IV only
- B. I and III only
- C. IV only
- D. II only
Calculate the time in which 4.8 kJ of energy would be expended when an electric heater of resistance 1.8 x 103Ω is used on a 240 V mains supply. (Neglect heat losses to the surrounding).
- A. 150.0s
- B. 90.0s
- C. 36.0s
- D. 20.0s