Waves

A string is hanging from a rigid support. A transverse pulse is excited at its free end. The speed at which the pulse travels a distance is proportional to

A train moves towards a stationary observer with speed . The train sounds a whistle and its frequency registered by the observer is . If the train's speed is reduced to , the frequency registered is . If the peed of sound is , then the ratio is

A source and an observer are moving towards each other with a speed equal to where is the speed of sound. The source is emitting sound of frequency The frequency heard by the observer will be

The equation of a spherical progressive wave is

Two wires made up of same material are of equal lengths but their radii are in the ratio 1:2. On stretching each of these two string by the same tension, the ratio between the fundamental frequencies is

In the 3rd overtone of an open organ pipe, there are (-stands for nodes and -for antinodes )

The time of reverberation of a room is one second. What will be the time (in seconds) of reverberation of a room, having all the dimensions double of those of room

Sound of the wavelength passes through a Quincke's tube, which is adjust to give a maximum intensity. Through what distance should the sliding tube be moved to give intensity ?

A car is moving with a speed of 72 towards a hill. Car blows horn at a distance of 1800 m from the hill. If echo is heard after 10s, the speed of sound is

Beats are produced with the help of two sound waves of amplitudes 3 and 5 The ratio of maximum to minimum intensity in the beats is