Question 21
Which of the following remains unchanged as light travels from one medium to the other?
i. speed.
ii. wavelength.
iii. frequency.
Options
A) i only
B) ii only
C) iii only
D) i and ii only
E) i and ii only
The correct answer is C.
Question 21
Which of the following statements about wave is not correct?
i. A wavefront is a line which contains all particles whose vibration are in phase.
ii. The direction of propagation of a wave is the link drawn parallel to the wavefront.
iii. A wavefront is a circle which is common to particles that are in the same state of disturbance
Options
A) i only
B) ii only
C) i and ii only
D) i and iii only
E) ii and iii only
The correct answer is E.
Question 21
What type of motion does the skin of a talking drum perform when its being struck with the drum stick?
Options
A) random
B) rational
C) vibratory
D) translational
E) circular
The correct answer is C.
Question 21
The sound from a bell in an enclosed jar gradually faints away while the jar is being evacuated. Which of the following explains this observation?
Options
A) the pressure is reduced
B) the sound waves are pumped out
C) the waves are absorbed in the inner walls
D) There is no more material medium
E) the air is disturbed
The correct answer is D.
Question 21
Which of the following statements is true of the diagram shown above?
Options
A) the two point, A and B are in phase
B) distance AB is half the wavelength of the wave
C) AC and BD are the amplitude of the wave
D) the two points A and B represents the wave crests
E) the wave has four crests
The correct answer is A.
Question 21
A man standing 300m away from the wall sounds a whistle. The echo from the wall reaches him 1.8sec. later. Calculate the velocity of sound in air.
Options
A) 540.0ms-1
B) 333.3ms-1
C) 270.0ms-1
D) 166.7ms-1
E) 83.3ms-1
The correct answer is B.
Explanation:
V =
= 333.33ms-1
Question 21
In which of the following is a stationary wave produced?
i. A vibrating turning fork held near the end of a resonance tube closed at one end.
ii. A string tightly stretched between two points and plucked at its middle.
iii. The tuning fork vibrating in air
Options
A) i only
B) ii only
C) i and ii only
D) ii and iii only
E) i, ii and iii
The correct answer is C.
Question 21
A particle of charge q and mass m moving with a velocity v enters a uniform magnetic field B in the direction of the field. The force on the particle is
Options
A) qvB
B) mqvB
C) mvB/q
D) qvB/m
The correct answer is A.
Question 21
If the frequency of the e.m.f. source in the a.c. circuit illustrated above is
Hz. What is the reactance of the inductor?
Options
A) 450
B) 0.9
C) 900
D) 567
E) 43
The correct answer is C.
Explanation:
x = 2
= 900
Question 21
Which of the following is a fundamental quantity?
Options
A) speed
B) density
C) length
D) impulse
E) energy
The correct answer is C.
Question 31
A body moves with a constant speed but has an acceleration. This is possible if it
Options
A) moves in a straight line
B) moves in a circle
C) is oscillating
D) is in equilibrum
E) has a varrying acceleration
The correct answer is B.
Question 31
A ball is projected horizontally from the top of a hill with a velocity of 20m-1. If it reaches the ground 4 seconds later, what is the height of the hill? (g = 10ms-2)
Options
A) 20m
B) 40m
C) 80m
D) 160m
E) 200m
The correct answer is C.
Explanation:
Initial horizontal velocity = 20ms-1
Initial vertical velocity = 0
s = ut +
= 0 × 5 × 42
= 80m
Question 31
A body moving with uniform acceleration has two points (5, 15) and (20, 60) on the velocity-times graph of its motion. Calculate the acceleration.
Options
A) 0.25ms-2
B) 3.00ms-2
C) 4.00ms-2
D) 9.00ms-2
E) 16.00ms-2
The correct answer is B.
Explanation:
slope = acceleration
a =
= 3ms-2
Question 31
The diagram above shows the position of a simple pendulum set in motion. At which of the positions does the pendulum have maximum kinetic energy?
Options
A) 5
B) 4
C) 3
D) 2
E) 1
The correct answer is C.
Question 31
An orange fruit drops to the ground from the top of a tree 45m tall. How long does it takes to reach the ground? (g = 10ms-2)
Options
A) 3.0s
B) 4.5s
C) 6.0s
D) 7.5s
E) 9.0s
The correct answer is A.
Explanation:
s = ut +
45 = 0 + 5t2
t = 3s
Question 31
Power is defined as the
Options
A) capacity to exert a force
B) product of force and time
C) product of force and distance
D) ability to do work
E) energy expended per unit time
The correct answer is E.
Question 31
The product PV where P is pressure and V is volume has the same unit as
Options
A) power
B) work
C) acceleration
D) impulse
E) force
The correct answer is B.
Explanation:
P =
V = m
PV = Nm unit of work
Question 31
The diagram represents a block-and-tackle pulley system on which an effort of 50N is just able to lift a load of weight W. If the efficiency of the machine is 40%. find the value of W
Options
A) 300N
B) 200N
C) 140N
D) 120N
E) 20N
The correct answer is D.
Explanation:
Eff =
40 =
MA = 240
W = L =
× 50
= 120N
Question 31
A boatman facing north wants to cross a flowing river to a point directly opposite its position at the other bank. If the river is flowing eastwards, in what direction should he row his boat?
Options
A) west
B) east
C) north-west
D) north-east
E) south-west
The correct answer is C.
Question 31
The diagram above represents six maximum and minimum thermometer. If the temperature of the surrounding falls, which of the following correctly states how the thermometer would respond to the change in temperature?
Options
A) S1, would move upward but S2 would not move
B) S1 would not move but S2 would move upwards
C) both S1 and S2 would move upwards
D) S1 would move downwards and S2 would move downward
E) S1 would move downwards and S2 would move downwards
The correct answer is B.