The minimum distance of reflector surface from the source for listening the echo of sound is :

(1) 28 m

(2) 18 m

(3) 19 m

(4) 16.5 m

If the amplitude of the sound is doubled and the frequency reduced to one-fourth, the intensity of sound at the same point will be :

(1) Increased by a factor of 2

(2) Decreased by a factor of 2

(3) Decreased by a factor of 4

(4) Unchanged

Intensity level of a sound of intensity I is 30 dB. The ratio $\frac{I}{I_0}$ is (Where I₀ is the threshold of hearing) 

(1) 3000

(2) 1000

(3) 300

(4) 30

If T is the reverberation time of an auditorium of volume V then :

(1) $T\propto \frac{1}{V}$

(2) $T\propto \frac{1}{V^2}$

(3) $T\propto V^2$

(4) $T\propto V$

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 correct graph between the frequency n and square root of density (ρ) of wire, keeping its length, radius and tension constant, is :

(1)

(2)

(3)

(4)

If the intensity is increased by a factor of 20; then how many decibels in the sound level increased?

1. 18

2. 13

3. 9

4. 7

Given below are two statements: