Two waves are said to be coherent, if they have:

A cylindrical resonance tube open at both ends, has a fundamental frequency ƒ, in air. If half of the length is dipped vertically in water, the fundamental frequency of the air column will be:

The wave described by

        y = 0.25 sin (10πx - 2πt),

where x and y are in metre and t in second, is a wave travelling with :

A wave of amplitude a = 0.2m, velocity v= 360 m/s and wavelength 60 m is travelling along positive x axis, then the correct expression for the wave is:

Equations of two progressive waves are given by y1 = a sin (ωt + ø₂). If amplitude and time period of resultant wave are same as that of both the waves, then (ø₁ - ø₂) is:

A 5.5 m length of string has a mass of 0.035 kg. If the tension in the string is 77 N, the speed of a wave on the string is:

The equation of a wave is given by

, where x and y are in metre and t in second, then velocity of wave is:

The driver of a car travelling with speed 30 ms-1 towards a hill sounds a horn of frequency 600 Hz. If the velocity of sound in air is 330 ms^-1, the frequency of reflected sound as heard by driver is:

Two sound waves with wavelengths 5.0 m and 5.5 m respectively, each propagate in a gas with velocity 330 m/s. We expect the following number of beats per second:

A whistle revolves in a circle with angular velocity ω = 20 rad/s using a string of length 50 cm. If the actual frequency of sound from the whistle is 385 Hz, then minimum frequency heard by the observer far away from the centre is: (velocity of sound v = 340 m/s)