Question

A progressive wave is represented by y = 12 sin (5t - 4x) cm. On this wave, how far away are the two points having phase difference of 90°?

Options

• `pi/2`cm

• `pi/4`cm

• `pi/8`cm

• `pi/16`cm

Answer 1

`bb(pi/8"cm")`

Explanation:

We have given y = 12sin(5t - 4x)cm

Comparing this equation with standard equation of progressive wave, y = Asin(ωt - kx)

we get A = 12

ω = 5

⇒ k = 4

Here, (ωt - kx) is phase difference = `pi/2`

∴ 5t - 4x = `pi/2`  when t = 0, 4x =  `pi/2`

∴ x = `pi/8`cm