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  particle  on  the  trough  of  a wave  at  any  instant  will come  to  the  mean  position  after  a  time  (T = time  period)

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

If  wave  y  = A  cos  is moving  along  x - axis,  the  shapes  of pulse  at  t = 0  and  t = 2  s

A  string  in  a  musical  instrument  is  50 cm  long  and  its  fundamental  frequency  is  800 Hz.  If  a  frequency  of  1,000 Hz  is  to  be  produced,  then  required length  of  string  is

Two trains move towards each other with the same speed. The speed of sound is 340 m/s. If the height of the tone of the whistle of one of them heard on the other changes times, then the speed of each train should be

A  tuning  fork  A  produces  4  beats/s  with  another  tuning  fork  B  of  frequency  320  Hz.  On  filing  one  of  the  prongs  of  A,  4  beat/s  are  again  heard  when  sounded  with  the  same  fork  B . Then,  the  frequency  of  the  fork  A  before  filing  is

An  observer  standing  by  the  side  of  a  road  hears  the  siren  of  an  ambulance,  which  is  moving  away  from  him.  If  the  actual  frequency  of  the  siren  is  2,000  Hz,  then  the  frequency  heard  by  the  observer  will  be

The transverse wave represented by the equation  has

A wave travelling along the x-axis is described by the equation  y(x,t) =  0.005 cos . If the wavelength and the time period of the wave are 0.08 and 2.0 s,respectively, then  and  in appropriate units are