Question

1.

A progressive wave in a stretched string has a speed of 20 ms and a frequency of 100 Hz. What is
the phase difference between two points 25 mm apart?
A zero
B pi/4 rad
c pi/2 rad
D pi tad

Answer 1

Option B

Step-by-step explanation:

As we know phase difference is equal to

`\psi = (2\pi )/(\lambda) * \Delta` ----Eq (1)

where

`\Delta` is the physical difference between two points = 0.025 m

`\lambda` is equal to
`(v)/(f)`

`\lambda = (20)/(100) = 0.2`

Substituting the given values in above equation, we get -

`\psi` =

`(2\pi )/(0.2) *0.025\\(\pi )/(4)`

Hence, option B is correct