1992 - WAEC Physics Past Questions and Answers - page 4
31
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
correct option: c
Users' Answers & Comments32
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
correct option: a
Users' Answers & Comments33
The diagram above shows a waveform in which energy is transferred from A to B in a time of 2.5 x 10-3s. Calculate the frequency of the wave
A
2.0 x 103Hz
B
1.0 x 103Hz
C
4.0 x 10-2Hz
D
1.0 x 10-3Hz
correct option: b
The waveform moved from A to B in \(2.5 \times 10^{-3}\) seconds.
From the diagram, A to B has \(2\frac{1}{2}\) complete oscillations between it, Therefore, the period of the oscillation is
\(\frac{2.5 \times 10^{-3}}{2.5} = 1 \times 10^{-3} s\)
\(Frequency = \frac{1}{Period}\)
= \(\frac{1}{1 \times 10^{-3}} = 1 \times 10^{3} Hz\)
34
Which of the following radiations have the highest frequency?
A
Radio waves
B
Light waves
C
X-rays
D
infra-red rays
correct option: c
Users' Answers & Comments35
How far from a cliff should a boy stand in order to hear the echo of his clap 0.9s later? (Speed of sound in air = 330 ms-1)
A
36.67m
B
74.25m
C
148.50m
D
297.00
36
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
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
correct option: d
Users' Answers & Comments37
Which of the following statements is not true?
A
Musical notes consist of the combination of sounds of regular frequency
B
The combination of overtones produced by an instrument determines the quality of the sound
C
the loudness of sound is determined by its frequency
D
the pitch of a note depends on the frequency of vibration of the source
correct option: a
Users' Answers & Comments38
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
39
The diagram above shows the magnetic field around a bar magnet which has its N-pole pointing north. The neutral points in the field are likely to occur at
A
1 and 2
B
3 and 4
C
5 and 6
D
7 and 8
correct option: d
Users' Answers & Comments40
A negatively charged rod is brought near the cap of a gold-leaf electroscope. The cap is earthed momentarily while the rod is near to it. The rod is then removed. Which of the following is correct?
A
The cap will be positively charged and the negatively charged leaves will diverge
B
The cap will be negatively charged and the positively charged leaves will diverge
C
The cap and the leaves will be positively charged
D
The cap and the leaves will be negatively charged.
correct option: c
Users' Answers & Comments