A train, standing in a station yard, blows a whistle of frequency 400 Hz in still air. The wind starts blowing in the direction from the yard to the station with a speed of 10m/s. Given that the speed of sound in still air is 340m/s,

(a) The frequency of sound as heard by an observer standing on the platform is 400Hz.

(b) The speed of sound for the observer standing on the platform is 350m/s.

(c) The frequency of sound as heard by the observer standing on the platform will increase.

(d) The frequency of sound as heard by the observer standing on the platform will decrease.

A set of 16 tuning forks are so arranged that each produce 4 beats with the previous one. If the frequency of last tuning fork is double that of first, the frequency of third tuning fork is

A pipe open at both ends produces a note of fundamental frequency V₁. When the pipe is kept with (1/3)^rd of its length in water, it produces a note of frequency V₂.The value of V₁/ V₂ is

A string of linear density 0.4 kg/m is stretched with force of 1000 N. A transverse wave is set up along it. The speed of the wave is

A particle is executing S.H.M. its potential energy v/s displacement graph is given by

The value of restoring force constant is :-

A heavy rope is suspended from rigid support. A wave pulse is set up at the lower end. Then