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 $y_1=A\sin (\pi x/L)\sin \omega t$ and energy is E₁, and in another experiment its displacement is $y_2=A\sin (2\pi x/L)\sin 2\omega t$ 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

An observer moves towards a stationary source of sound with a speed 1/5^th of the speed of sound. The wavelength and frequency of the sound emitted are λ and f respectively. The apparent frequency and wavelength recorded by the observer are respectively :

1. $1.2f, \lambda$

2. $f,1.2\lambda$

3. $0.8f,0.8\lambda$

4. $1.2f,1.2\lambda$

Consider ten identical sources of sound all giving the same frequency but having phase angles which are random. If the average intensity of each source is I₀, the average of resultant intensity I due to all these ten sources will be :

(1) I = 100 I₀

(2) I = 10 I₀

(3) I = I₀

(4) $I=\sqrt{10}{I}_0$