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

A wavelength 0.60 cm is produced in air and it travels at a speed of 300 ms^–1. It will be an 

(1) Audible wave

(2) Infrasonic wave

(3) Ultrasonic wave

(4) None of the above

An observer standing near the seashore observes 54 waves per minute. If the wavelength of the water wave is 10m then the velocity of a water wave is :

(1) 540 ms^-1

(2) 5.4 ms^-1

(3) 0.184 ms^-1

(4) 9 ms^-1

The equation of a wave is $y=2\sin \pi (0.5x-200t)$, where x and y are expressed in cm and t in sec. The wave velocity is :

1. 100 cm/sec

2. 200 cm/sec

3. 300 cm/sec

4. 400 cm/sec

Equation of a progressive wave is given by

$y=0.2\cos \left(0.04\pi t+0.02\pi x-\frac{{\displaystyle \pi }}{{\displaystyle 6}}\right)$

The distance is expressed in cm and time in second. What will be the minimum distance between two particles having the phase difference of π/2 :

1. 4 cm

2. 8 cm

3. 25 cm

4. 12.5 cm

Two waves are given by $y_1=a\sin (\omega t-kx)$ and $y_2=a\cos (\omega t-kx)$. The phase difference between the two waves is :

(1) $\frac{\pi }{4}$

(2) π

(3) $\frac{\pi }{8}$

(4) $\frac{\pi }{2}$

If the amplitude of waves at distance r from a point source is A, the amplitude at a distance 2r will be :

(1) 2A

(2) A

(3) A/2

(4) A/4

A wave is reflected from a rigid support. The change in phase on reflection will be : 

(1) π/4

(2) π/2

(3) π

(4) 2π

A plane wave is represented by $x=1.2\sin (314t+12.56y)$

Where x and y are distances measured along in x and y direction in meters and t is time in seconds. This wave has 

(1) A wavelength of 0.25 m and travels in + ve x-direction

(2) A wavelength of 0.25 m and travels in + ve y-direction

(3) A wavelength of 0.5 m and travels in – ve y-direction

(4) A wavelength of 0.5 m and travels in – ve x-direction