Two waves of wavelength 50 cm and 51 cm produce 12 beats.  The speed of sound is

The phase difference between two waves represented by

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

Velocity of sound waves in air is 330 m/s.  For a particular sound wave in air, path difference of 40 cm is equivalent to phase difference of 

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 and equal to 1 gm^-1.  When both the strings vibrate simultaneously the number of beats is  

The equation of a sound wave is given as y = 0.005 sin (62.4x+ 316t ).  The wavelength of this wave is

Two strings A and B have lengths l_A and l_B and carry masses M_A and M_B at their lower ends, the upper ends being supported by rigid supports.  If n_A and n_B are the frequencies of their vibrations and n_A = 2n_B, then

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 fequency n + n₁.  Then (If the sound velocity in air is 300 m/s)

A wave enters to water from air.  In air frequency, wavelength, intensity and velocity are

In water the corresponding quantities are 

Two waves are said to be coherent, if they have

A pulse of a wave train travels along a stretched string and reaches the fixed end of the string.  It will be reflected back with