Friday, 4 November 2016

8 Waves MCQs with solution

between mechanical and electromagnetic waves are important topics.

Waves questions

1.            A physical system undergoing forced vibrations is called
(a)        harmonic oscillator           (b) driven oscillator
(c) damped oscillator             (d) all of these

2.            The waves produced in a microwave oven have a frequency equal to
(a)        2450 Hz                            (b) 2450 kHz
(c) 2450 MHz                        (d) none of these

3.            On increasing the amplitude of an oscillator twice, its energy
(a)        increases two times          (b) decreases two times
(c) decreases four times        (d) increases four times

4.            The SI unit of force constant is the same as that of
(a)        force                                 (b) pressure
(c) surface tension                 (d) stress

5.            When a particle is in uniform circular motion, its projection along the diameter axis executes
(a)        linear motion                    (b) circular motion
(c) vibratory motion               (d) simple harmonic motion

6.            On shifting a simple pendulum from pole to equator, we notice
(a)        an increase in its time period
(b)        a decrease in its time period
(c)        a change in its mass
(d)       no change either in mass or time period

7.            What happens to the time period of a mass-spring system if the spring is replaced by a more stiff spring?
(a)        Increases                          (b) Decreases
(c) Remains the same            (d) Can not be predicted.

8.            The amplitude of a forced oscillator depends upon the
(a)        natural frequency of the oscillator
(b)        frequency of the driving force
(c)        amount of damping present
(d)       all of these
9.            A shock absorber is a
(a)        harmonic oscillator           (b) driven oscillator
(c) damped oscillator             (d) all of these

10.         In damped harmonic oscillator, the loss of energy is due to
(a)        the decrease in frequency of the oscillator
(b)        an increase of its time period
(c)        a decrease in its amplitude
(d)       all of these

11.         Sound waves do not travel in vacuum because these are
(a)        longitudinal waves           (b) composed of compressions
(c) mechanical waves            (d) low frequency waves

12.         In a stationary wave, the antinodes are located at
(a)        the ends                           (b) the middle
(c) between nodes                 (d) anywhere

13.         A simple pendulum suspended from the ceiling in an elevator has time period T when the elevator is at rest. When the elevator falls freely, its time period becomes
(c) zero                                 (d) infinite

14.         When two identical waves are superimposed on each other, the velocity of the resultant wave
(a)        decreases                         (b) increases
(c) remains the same             (d) becomes zero

15.         Set of frequencies which are an integral multiple of the fundamental frequency are called
(a)        beat frequencies               (b) driving frequencies
(c) natural frequencies          (d) overtones

16.         The speed of sound in a medium depends upon
(a)        elasticity of the medium (b) density of the medium
(c) amplitude of sound           (d) both ‘a’ and ‘b’

17.         Which one of the following properties of sound is affected by a change in the temperature of air?
(a)        Frequency                         (b) Amplitude
(c) Wavelength                      (d) Intensity

18.         When a wave enters a medium, which of its following parameters remains unchanged?
(a)        Wavelength            (b) Speed

(c) Frequency                        (d) Intensity