CBSE
Multiple Choice QuestionsWhen the length of the vibrating segment of a sonometer wire is increased by 1%, the percentage change in its frequency is
100/101
99/100
1
2
A tuning fork A produces 4 beats/s with another tuning fork B of frequency 320 Hz. On filling one of the prongs of A, 4 beats/s are again heard when sounded with the same fork B. Then, the frequency of the fork A before the filling is
328 Hz
316 Hz
324 Hz
320 Hz
The equation of a simple harmonic wave is given by where x and y are in metre and time is in second. The period of the wave in second will be
0.04
0.01
1
5
A man stands in a narrow, steep-sided valley. When he shouts he hears two echoes, one after 1s and other after 2s.If the velocity of sound in air is 330 m/s, the width of the valley is
330 m
495 m
660 m
990 m
A cylindrical tube, open at both ends emits a fundamental frequency f in air. The tube is dipped vertically in water, so that half of it is in water. The fundamental frequency of air column is now
f/2
3f/4
f
2f
The end correction of a resonance column is 1.0 cm. If the shortest length resonating with the tuning fork is 15.0 cm, the next resonating length will be
31 cm
45 cm
46 cm
47 cm
When a certain volume of water is subjected to 100 kPa pressure, the volume of water decreases by 0.005%. The speed of sound in water must be
140 m/s
300 m/s
1400 m/s
5000 m/s
Assertion: Soldiers are asked to break steps while crossing the bridge.
Reason: The frequency of thick marching may be equal to the natural frequency of bridge and may lead to resonance which can break the bridge.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If assertion is false but reason is true.
A source of frequency 240 Hz is moving towards an observer with a velocity of 20 m/s. The observer is now moving towards the source with a velocity of 20 m/s. Apparent frequency heard by observer, if velocity of sound is 340 m/s, is
268 Hz
270 Hz
360 Hz
240 Hz
The observed wavelength of light coming from a distant galaxy is found to be increased by 0.5% as compared with that coming from a
terrestrial source. The galaxy is
stationary with respect to the earth
approaching the earth with velocity of light
receding from the earth with velocity of light
receding from the earth with a velocity
equal to 1.5 106 m/s.
