2008 - WAEC Physics Past Questions and Answers - page 3
21
The working principle of a pressure cooker is based on the
A
increase in the volume of steam inside it
B
complete trapping of heat inside it
C
increase in the pressure of the pot
D
decrease in the pressure of the pot
correct option: c
Users' Answers & Comments22
It takes a shorter time for a liquid to boil at the top of a mountain than at the base because at the top, the
A
temperature is higher
B
pressure is lower
C
humidity is higher
D
temperature is constant
correct option: b
Users' Answers & Comments23
Light is considered as a transverse wave because it travels
A
through material without causing disturbance of the medium
B
through space with constant speed
C
in a direction parallel to the plane containing the electric and magnetic fields
D
in a direction perpendicular to the plane containing the electric and magnetic fields
correct option: d
Users' Answers & Comments24
In the day time, it is possible to see under shady areas such as under a tree because light has undergone
A
internal reflection
B
refraction
C
diffraction
D
diffuse reflection
correct option: d
Users' Answers & Comments25
The distance between a concave mirror and an object placed in front of it is 1.0m. If the raduis of curvature of the mirror is 4.0m, the image formed will be
A
2.00m behind the mirror
B
2.00m in front of the mirror
C
1.25m in front of the mirror
D
1.25m behind the mirror
correct option: a
\(\frac{1}{v} = \frac{1}{f} - \frac{1}{u}\)
\(\frac{1}{2} - \frac{1}{1} = \frac{1 - 2}{2} = -2\)
Users' Answers & Comments\(\frac{1}{2} - \frac{1}{1} = \frac{1 - 2}{2} = -2\)
26
The image of an object formed by a convex mirror is
A
real, errect and enlarged
B
real, inverted and enlarged
C
virtual, erect and diminished
D
virtual, erect and enlarge
correct option: c
Users' Answers & Comments27
When viewed straight down, a fish in a pond is
A
father below than it apperas to be
B
mearer than it appears to be
C
found at exactly the same point it is seen
D
seen beside its image
correct option: b
Users' Answers & Comments28
A converging lens and a screen are placed 20 cm and 80 cm respectively from an object in a straight line so that a sharp image of the object is formed on the screen. If the object is 3cm high. Calculate the height of the image formed
A
1 cm
B
9cm
C
12cm
D
15cm
correct option: b
\(\frac{v}{u} = \frac{hi}{ho} = \frac{60}{20} = \frac{hi}{3}\)
hi = 9cm
Users' Answers & Commentshi = 9cm
29
Which of the following defects of vision is as a result of the eye ball being too long?
A
long sight
B
astigmatism
C
short sight
D
loss of accommodation
correct option: c
Users' Answers & Comments30
a sound wave is produced fron a source ans an echo is heard t seconds afterwards. If d is the distance of the reflecting surface from the source, v the speed, p the wavelength and T the period of the wave, then
A
d = \(\frac{2t}{\lambda}\)
B
d = \(\frac{\lambda t}{2T}\)
C
d = \(\frac{2T}{\lambda t}\)
D
d = \(\frac{\lambda T}{2t}\)
correct option: b
V = \(\frac{2d}{t}\)
f\(\lambda = \frac{2d}{t} = \frac{\lambda}{T} = \frac{2d}{t}\)
Users' Answers & Commentsf\(\lambda = \frac{2d}{t} = \frac{\lambda}{T} = \frac{2d}{t}\)