2009 - WAEC Physics Past Questions and Answers - page 3
21
Which of the following factors affect the rate of evaporation of a liquid? i. Exposed surface area ii Temperature of the surroundings iii. Thermal capacity of the liquid iv. Relative humidity of the surroundings
A
ii and iii only
B
ii, iii and iv only
C
i, iii and iv only
D
i, ii amd iv only
correct option: d
Users' Answers & Comments22
The maximum displacement of a vibrating tunning fork is its
A
amplitude
B
frequency
C
period
D
wavelength
correct option: a
Users' Answers & Comments23
A boat is rocked by waves of speed 30ms-1 whose successive crest are 10m apart. Calculate the rate at which the boat recieves the waves
A
30s-1
B
10s-1
C
3s-1
D
1s-1
24
Which of the following waves is not transverse
A
light waves
B
sound waves
C
sea waves
D
radio waves
correct option: b
Users' Answers & Comments25
Light travelling through a small pinhole usually does not make a shadow with a distinct sharp edge because of
A
diffraction
B
inteference
C
reflection
D
refraction
correct option: a
Users' Answers & Comments26
The angle of incidence of a ray of light on a plane mirror is 55o. Determine the angle between the reflected ray and the mirror
A
35o
B
45o
C
55o
D
110o
correct option: a
Users' Answers & Comments27
A concave mirror forms a magnified and errect image only when the object is placed
A
at the centre of curvature
B
at the focus
C
between the focus and the pole of the mirror
D
beyound the radius of curvature
correct option: c
Users' Answers & Comments28
A thin lens is placed 50cm from an illustrated object. The image produced has linear magnification of \(\frac{1}{4}\). Calculate the power of the lens in dioptres
A
2.5D
B
5.0D
C
10.0D
D
25.0D
correct option: c
\(\frac{1}{v} = \frac{1}{u}\)
m = \(\frac{v}{u} = \frac{1}{4} = \frac{v}{50}\)
v = 12.5
But \(\frac{1}{v} + \frac{i}{u} = \frac{1}{f}\)
= \(\frac{1}{50} + \frac{1}{12.5} = f\)
f = 10m
P = \(\frac{100}{10} = 10D\)
Users' Answers & Commentsm = \(\frac{v}{u} = \frac{1}{4} = \frac{v}{50}\)
v = 12.5
But \(\frac{1}{v} + \frac{i}{u} = \frac{1}{f}\)
= \(\frac{1}{50} + \frac{1}{12.5} = f\)
f = 10m
P = \(\frac{100}{10} = 10D\)
29
Which of the following characteristics of light determines its colour?
A
velocity
B
wavelength
C
amplitude
D
intensity
correct option: b
Users' Answers & Comments30
Which of the following is not a part of the electro-magnetic spectrum?
A
x-rays
B
microwaves
C
infrared radiation
D
alpha rays
correct option: d
Users' Answers & Comments