2003 - WAEC Physics Past Questions and Answers - page 3
21
The horizontal floor of a water reservoir appears to be 1.0m deep when viewed vertically from above. If the refractive index of water is 1.35, calculate the real depth of the reservoir
A
2.35m
B
1.35m
C
1.00m
D
0.35m
correct option: b
n = \(\frac{R.d}{A.d}\)
1.35 = \(\frac{R.d}{1}\)
R.d = 1.35m
Users' Answers & Comments1.35 = \(\frac{R.d}{1}\)
R.d = 1.35m
22
A converging lens has a focal length of 5cm. Determine its power
A
+20.0
B
+0.2
C
-20.00
D
-0.2
23
Which of the following pairs of rays shows the widest separation in the spectrum of white light?
A
green and blue
B
orange and indigo
C
blue and violet
D
red and yellow
correct option: b
Users' Answers & Comments24
Which of the following statements about the human eye and the camera is correct?
A
both form virtual image of objects
B
the image formed by the eye is upright in the retina while that formed by the camera is inverted on the film
C
the inside of both of them is blackened to absorb unwanted light
D
the focal length of both eye lens and the camera lens can be varied
correct option: c
Users' Answers & Comments25
The speed of sound in air is is directly proportional to
A
its temperature on the celsius scale
B
ite temperature in the thermodynamic scale
C
the cube root of its temperature on its celcius csale
D
the square roor of its temperature on the absolute scale
correct option: d
Users' Answers & Comments26
A sonometer wire of linear density 0.08kg m-1 subjected to a tension of 800N is plucked. Calculate the speed of a pulse which moves from one end of the wire to the other
A
179.0ms-1
B
100.0ms-1
C
15.8ms-1
D
8.0ms-1
correct option: b
v = \(\sqrt{\frac{T}{m}} = \sqrt{\frac{800}{0.08}} = 100\)m/s
Users' Answers & Comments27
Which of the following instruments gives a pure note when sounded?
A
talking drum
B
siren
C
tunning fork
D
guitar
correct option: c
Users' Answers & Comments28
Which of the following features of an electrostatic line of force is not correct?
A
it is an imaginary line which a positive charge will describe if it is free to move
B
the tangent drawn at any point on a curved line of force shows the direction of the electric field intensity at that point
C
it is sometimes curved
D
it can cross another line of force in a region of intense electric field
correct option: d
Users' Answers & Comments29
Which of the following statement about force is correct ?
A
electrostatic, gravitational and magnetic forces are always attractive
B
electric, gravitational and magnetic field obeys inverse square law
C
field lines are real but their corresponding field are imaginary
D
field lines and their corresponding fields are both real
correct option: c
Users' Answers & Comments30
A positively charged glass rod is placed by near the cap of a positively charge electroscope. The divergence of the leaf is observed to
A
decrease
B
increase
C
remain the same
D
increase and collapse immediately
correct option: b
Users' Answers & Comments