The intensity level due to two waves of the same frequency in a given medium are 1 bel and 5 bel. Then the ratio of amplitudes is :
(1) 1 : 4
(2) 1 : 2
(3) 1 : 104
(4) 1 : 102
Of the following the one which emits the sound of a higher pitch is :
(1) Mosquito
(2) Lion
(3) Man
(4) Woman
Two waves having sinusoidal waveforms have different wavelengths and different amplitudes. They will be having :
(1) Same pitch and different intensity
(2) Same quality and different intensity
(3) Different quality and different intensity
(4) Same quality and different pitch
The ends of a stretched wire of length L are fixed at x = 0 and x = L. In one experiment, the displacement of the wire is and energy is E1, and in another experiment its displacement is and energy is E2. Then :
(1) E2 = E1
(2) E2 = 2E1
(3) E2 = 4E1
(4) E2 = 16E1
In the experiment for the determination of the speed of sound in air using the resonance column method, the length of the air column that resonates in the fundamental mode, with a tuning fork is 0.1 m. when this length is changed to 0.35 m, the same tuning fork resonates with the first overtone. Calculate the end correction :
(1) 0.012m
(2) 0.025m
(3) 0.05m
(4) 0.024m
Two identical stringed instruments have a frequency 100 Hz. If the tension in one of them is increased by 4% and they are sounded together then the number of beats in one second is :
(1) 1
(2) 8
(3) 4
(4) 2
The difference between the apparent frequency of a source of sound as perceived by an observer during its approach and recession is 2% of the natural frequency of the source. If the velocity of sound in air is 300 m/sec, the velocity of the source is : (It is given that velocity of source << velocity of sound)
(1) 6 m/sec
(2) 3 m/sec
(3) 1.5 m/sec
(4) 12 m/sec
Two whistles A and B produce notes of frequencies 660 Hz and 596 Hz respectively. There is a listener at the mid-point of the line joining them. Now the whistle B and the listener start moving with speed 30 m/s away from the whistle A. If the speed of sound be 330 m/s, how many beats will be heard by the listener :
(1) 2
(2) 4
(3) 6
(4) 8
A source producing the sound of frequency 170 Hz is approaching a stationary observer with a velocity of 17 ms–1. The apparent change in the wavelength of sound heard by the observer is (speed of sound in air = 340 ms–1)
1. 0.1m
2. 0.2m
3. 0.4m
4. 0.5m
A police car moving at 22 m/s, chases a motorcyclist. The policeman sounds his horn at 176 Hz, while both of them move towards a stationary siren of frequency 165 Hz. Calculate the speed of the motorcycle, if it is given that motorcyclist does not observe any beats.
(Speed of sound=330 m/s)
(1) 33 m/s
(2) 22 m/s
(3) Zero
(4) 11 m/s