The phase difference between two pointsw separated by 1 in a wave of frequency 120 Hz is 90^(@).The wave velocity will be :

The phase difference between two pointsw separated by 1 in a wave of f

1.	The phase difference between two pointsw separated by 1 in a wave of frequency 120 Hz is 90^(@).The wave velocity will be :
Answer» `480 m//s` `180 m//s` `720 m//s` `240 m//s` SOLUTION :`Delta X= 1 m Delta varphi=90^(@)=(pi)/(2) "rad", gamma =12 Hz` As `Delta varphi =(2PI)/(LAMBDA)xx Delta x` (or) `(pi)/(2)=(2pi)/(lambda)xx1` (or) `lambda=4m` `v= gamma lambda120xx4= 480 m//s`