Question

Wavelength of a travelling wave is 20 cm. What is the phase angle between the two points separated through a distance of 25cm?

A2

B2.5

C3

D1

Answer 1

=2pi×25/20 sp the phase angle is ...b ..2.5pi

Answer 2

General Expression relating phase difference and path difference is:

$\Delta \phi = \dfrac{2\pi}{ \lambda} \times \Delta d$

$\implies\Delta \phi = \dfrac{2\pi}{20} \times (x2 - x1)$

$\implies\Delta \phi = \dfrac{2\pi}{20} \times 25$

$\implies\Delta \phi = \dfrac{2\pi}{4} \times 5$

$\implies\Delta \phi = \dfrac{\pi}{2} \times 5$

$\implies\Delta \phi = \dfrac{5\pi}{2} \: radians$

So, phase difference is 5π/2 radians.