If v_m is the velocity of sound in moist air, v_d is the velocity of sound in dry air, under identical conditions of pressure and temperature 

(1) v_m > v_d

(2) v_m < v_d

(3) v_m = v_d

(4) v_mv_d = 1

A source of the sound of frequency 600 Hz is placed inside water. The speed of sound in water is 1500 m/s and in the air is 300 m/s. The frequency of sound recorded by an observer who is standing in the air is : 

1. 200 Hz

2. 3000 Hz

3. 120 Hz

4. 600 Hz

An underwater sonar source operating at a frequency of 60 kHz directs its beam towards the surface. If the velocity of sound in air is 330 m/s, the wavelength and frequency of waves in air are: 

(1) 5.5 mm, 60 kHz

(2) 330 m, 60 kHz

(3) 5.5 mm, 20 kHz

(4) 5.5 mm, 80 kHz

It is possible to distinguish between the transverse and longitudinal waves by studying the property of :

1. Interference

2. Diffraction

3. Reflection

4. Polarisation

Water waves are 

(1) Longitudinal

(2) Transverse

(3) Both longitudinal and transverse

(4) Neither longitudinal nor transverse

The waves in which the particles of the medium vibrate in a direction perpendicular to the direction of wave motion is known as 

1. Transverse wave

2. Longitudinal waves

3. Propagated waves

4. None of these

What is the phase difference between two successive crests in the wave?

(1) π

(2) π/2

(3) 2π

(4) 4π

A wave of the frequency of 500 Hz has a velocity of 360 m/sec. The distance between two nearest points 60° out of phase is :

(1) 0.6 cm

(2) 12 cm

(3) 60 cm

(4) 120 cm

Sound waves of wavelength greater than that of audible sound are called :

(1) Seismic waves

(2) Sonic waves

(3) Ultrasonic waves

(4) Infrasonic waves

The ratio of masses of nitrogen and oxygen is 14:16. The temperature at which the speed of sound in nitrogen will be same at that in oxygen at 55°C is -

1. 35°C

2. 48°C

3. 65°C

4. 14°C