CBSE
Multiple Choice QuestionsA set of 24 tuning forks are so arranged that each gives 6 beats/s with the previous one. If the frequency of the last tuning fork is double than that of the first, frequency of the second tuning fork is
138 Hz
132 Hz
144 Hz
276 Hz
When the two waves y1 = a sin ωt and y2 = a cos ωt are superimposed, then resultant amplitude is
a
2a
The equation where the symbols carry the usual meaning and A, T and λ are positive, represents a wave of
amplitude 2 A
period T/λ
speed xλ
speed
A pipe open at both the ends produces a note of fundamental frequency f1 . When the pipe is kept with th of its length in water, it produces a note of fundamental frequency f2 . The ratio of is
2
The equation of a progressive wave can be given by y = 15 sin (660 − 0.02 x) cm. The frequency of the wave is
330 Hz
342 Hz
365 Hz
660 Hz
A train moves towards a stationary observer with speed 34 ms-1 . The train sounds a whistle and its frequency registered by the observer is v1 , If the train's speed is reduced to 17 ms-1, the frequency registered is v2. If the speed of sound is 340 ms-1 , then the ratio v1 /v2 is
2
Two vibrating strings of the same material but lengths L and 2 L have radii 2r and r respectively. They are stretched under the same tension. Both the strings vibrate in their fundamental modes, the one of length L with frequency v1 and the other with frequency v2 . The ratio v1 / v2 is
2
4
8
1
A closed organ pipe and an open organ pipe are tuned to the same fundamental frequency. The ratio of their lengths is
1 : 1
2 : 1
1 : 4
1 : 2
A red coloured object illuminated by mercury vapour lamp, when seen through a green filter, will appear
red
blue
violet
black
An observer standing near the sea shore 54 min. If the wavelength of the water wave is 10 m, then the velocity of water wave is
540 ms-1
5.4 ms-1
0.184 ms-1
9 ms-1
