A vehicle, with a horn of frequency n is moving with a velocity of 30 m/s in a direction perpendicular to the straight line joining the observer and the vehicle. The observer perceives the sound to have a frequency n + n₁.Then n1 is equal to : ( the sound velocity in air is 300 m/s)

Each of the two strings of length 51.6 cm and 49.1 cm are tensioned separately by 20 N force. Mass per unit length of both the strings is same adn equal to 1 gm^-1. When both the strings vibrate simultaneously the number of beats 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 enters to water from air. In air frequency, wavelength, intensity and velocity are n₁, λ₁, l₁ and v₁ respectively. In water the corresponding quantities are n₂, λ₂, l₁and v₂ respectively, then:

Which one of the following statements is true?

The frequency of sinusoidal wave, 0.40 cos (2000t + 0.80) would be:

The phase difference between two waves, represented by

where x is expressed in metre and t is expressed in second, is approximately:

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:

A pointer source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at distance of 2m and 3m respectively from the source. The ratio of the intensities of the waves at P and Q 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: