The  apparent  frequency  of  a  note  is  200  Hz,  when  a  listener  is  moving  with  a  velocity  of  40 ms^-1  towards  a  stationary  source.  When  he  moves  away  from  the  same  source  with  the same  speed,  the  apparent  frequency  of  the  same  note  is  160 Hz.  The  velocity  of  sound  in  air  in  m/s  is

A wave y= a sin 

A metal wire of linear mass density of 9.8 gm^-1 is stretched with a tension of 10 kg wt between two rigid  supports 1 m  apart. The wire passes at its middle point between the poles of a permanent magnet and it vibrates in resonance, when carrying an alternating current of frequency v. The frequency v of the alternating source is

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

A  closed  organ  pipe  and  an  open  pipe  of  the  same  length  produce  four  beats  per  second,  when  sounded  together.  If  the  length  of  the  closed  pipe  is  increased,  then  the  number  of  beats  will

Two  cars  approach  a stationary  observer  from  opposite  sides  as  shown  in  the  figure.

A  tube  closed  at  one  end  containing  air  produces  fundamental  note  of  frequency  512  Hz.  If  the  tube  is  open  at  both  the  ends,  the  fundamental  frequency  will  be.

A  person  is  standing  on  a  railway  platform  and  a  train  is  approaching  to  him,  what  is  maximum  wavelength  of  sound  he  can  hear  ?  Wavelength  of  whistle  =  1 m,  speed  of  sound  in  air  =  330  m/s,  speed  of  train  =  36  km/h.

Newton's  formula  for  the  velocity  of  sound  in  gases  is

Tube A has both ends open, while tube B has one end closed, otherwise they are identical. The ratio of fundamental frequency of tubes A and B is.