2001 - WAEC Physics Past Questions and Answers - page 3
21
Humidity is used to describe the amount of
A
air in water vapour
B
cloud available in the atmosphere
C
air in equal volume of cloud
D
water vapour in the amosphere
correct option: d
Users' Answers & Comments22
Surface waves travelling in deep water at 15ms-1 are incident at a shallow water boundary. If the angles of incidence and refraction are 45o and 30o respectively. Calculate the speed of the waves in shallow water
A
8.1ms-1
B
10.0ms-1
C
10.6ms-1
D
22.5ms-1
correct option: c
n = (\frac{\sin 45}{\sin 30} = 1.4142)
n = (\frac{15m/s}{x})
x = (\frac{15}{1.4142}) = 10.6m/s
23
An incident ray is reflected normally by a plane mirror onto a screen where it forms a bright spot. The mirror and screen are parallel and 1m apart. If the mirror is rotated through 5o, calculate the displacement of the spot
A
8.7cm
B
10.0cm
C
15.4cm
D
17.6cm
24
Convex spherical mirrors are preferred to plane mirrors as driving mirrors because
A
the image produce is upright and clearly visible
B
it provides a wider field of view
C
the image produce is errect and diminished
D
the image produced is not laterally inverted
correct option: b
Users' Answers & Comments25
An object is placed 20cm from a lens. If an image is formed on a screen 260cm away from the lens, calculate the magnification of the image
A
28
B
26
C
24
D
13
26
A piece of cloth appears green in sunlight. When held in red light, it will appear
A
green
B
blue
C
red
D
black
correct option: d
Users' Answers & Comments27
Dispersion of white light by a glass prism occurs because
A
white light consist of a mixture of seven different colour
B
the refractive index of glass is different from each constituent colour of white light
C
the speed of each colour of light in the glass is proportional to the refractive index of glass for each colour
D
the speed of each colour of light in the glass is proportional to the angle of refraction in he prism
correct option: d
Users' Answers & Comments28
Which of the following statements about sound is correct?
A
when sound travels from air to a denser medium, it is refracted away from the normal at the point of incidence
B
sound travels faster in air than in water
C
the wavelength of sound changes when it travels from to water
D
the frequency of it travels from air to water
correct option: c
Users' Answers & Comments29
The diagram above shows the wire of a sonometer box set into resonance by a vibrating tuning fork of frequency f, when the wire is stretched by a tension T, the resonating length of the wire is I while the wavelength of the sound produced is \(\lambda\). Which of the following statements is not correct? The wave produced on the wire is
A
stationary and lonitudinal
B
stationary and mechanical
C
mechanical and longitudinal
D
progessive and transverse
correct option: a
Users' Answers & Comments30
The diagram above shows the wire of a sonometer box set into resonance by a vibrating tuning fork of frequency f, when the wire is stretched by a tension T, the resonating length of the wire is I while the wavelength of the sound produced is \(\lambda\). Which of the following statements about the frequency of vibration of the wire is not correct?
A
proportional to the mass per unit length of the wire
B
equal to the frequency of the tuning fork
C
inversely proportional to the length of the wire
D
proportional to the sqare root of the tension
correct option: a
Users' Answers & Comments