2007 - WAEC Physics Past Questions and Answers - page 3
21
A relative density bottle of volume 50cm3 is completely filled with a liquid at 30oC. It is then heated to 80oC such that 0.75cm3 of the liquid is expelled. Calculate the apparent cubic expansivity of the liquid.
A
0.00030k-1
B
0.00032k-1
C
0.01970k-1
D
0.02030k-1
correct option: a
Ya = \(\frac{\text{Vol. expelled}}{\text{Vol. left x temp. change}} = \frac{0.75}{49.25 \times 50}\)
= 0.00030k-1
Users' Answers & Comments= 0.00030k-1
22
A body of mass 200g and specific heat capacity 0.4Jg-1k-1 cools from 37oC to 31oC. Calculate the quantity of the heat released by the body.
A
4800J
B
1200J
C
480J
D
202J
23
According to the kinetic theory of gasses, which of the following property of a gas can be affected by the collision of the gas molecule with the walls of the container?
A
temperature
B
energy
C
viscosity
D
pressure
correct option: d
Users' Answers & Comments24
The pressure of a fixed mass of an ideal gas at 27°C is 3 pa. The gas is heated at a constant volume until its pressure is 5 pa. Determine the new temperature of the gas.
A
100oC
B
227oC
C
273oC
D
500oC
correct option: b
\(\frac{P_1}{T_1} = \frac{P_2}{T_2} = \frac{3}{300} = \frac{5}{T_2}\)
T\(_2\) = 500°C
°C = 500 - 273 = 227°
25
Which of the following wave is electromagnetic?
A
x-rays
B
sound waves
C
water waves
D
tidal waves
correct option: a
Users' Answers & Comments26
The distance between two points P and Q, along a wave is 0.05m. If the wave length of the wave is 0.10m, determine the phase angle between P and Q in radians
A
0.1\(\pi\)
B
\(\pi\)
C
2\(\pi\)
D
10\(\pi\)
correct option: b
Users' Answers & Comments27
Which of the following phenomena is not a direct consequence of rectilinear propagation of light?
A
lunar and solar eclipses
B
images of objects in a pin hole camera
C
diffraction of light
D
shadows of opaque object
correct option: c
Users' Answers & Comments28
An object is placed 10cm in front of a plane mirror. If it is moved 8cm away father away from the mirror, determine the distance of the final image from the mirror
A
2cm
B
9cm
C
16cm
D
18cm
correct option: d
Users' Answers & Comments29
In which of the following piece of apparatus is the radius of curvature equal to twice the focal length?
A
converging lens
B
diverging lens
C
converging mirror
D
parabolic mirror
correct option: c
Users' Answers & Comments30
When an object is placed at the centre of curvature of a concave mirror, its image is formed at
A
the focus
B
infinity
C
the centre of curvature
D
a distance twice the radius of curvature
correct option: c
Users' Answers & Comments