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

A hospital uses an ultrasonic scanner to locate tumours in a tissue.  The operating frequency of the scanner is 4.2 MHz.  The speed of a sound in a tissue is 1.7 km/s.  The speed of sound in a tissue is 1.7 km/s.  The wavelength of sound in tissue is close to

Equations of two progressive waves are given by 

If amplitude and time period of resultant wave are same as that of both the waves, then 

If the amplitude of sound is doubles and the frequency reduced to one-fourth, the intensity of sound at the same point will

A car is moving towards a high cliff.  The car driver sounds a horn of frequency f.  The reflected sound heard by the driver has a frequency 2f.  If v be the velocity of sound, then the velocity of the car, in the same velocity units, will be

A star which is emitting radiation at a wavelength of 5000 is approaching the earth with a velocity of 1.50 x10⁶ m/s. The change in wavelength of the radiation as received on the earth is

An observer moves towards a stationary  source of sound with a speed of the speed of sound . The wavelength and frequency of the source emitted are respectively.  The apparent frequency and wavelength recorded by the observer are respectively

A closed organ pipe (closed at one end) is excited to support the third overtone.  It is found that air in the pipe has

Two waves are approaching each other with a velocity of 20 m/s and frequency n.  The distance between two consecutive nodes is

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