Question

A progressive wave of frequency 50 Hz is travelling with velocity 350 m/s through a medium. The change in phase at given time interval of 0.01s is

• A. \(\frac{π}{4}\,\text{rad}\)
• B. \(\frac{π}{2}\,\text{rad}\)
• C. \(π\,\text{rad}\)
• D. \(\frac{3π}{2}\,\text{rad}\)

Hint:

Phase change equals angular frequency times the time interval.

Answer 1

The Correct Option is C

Step 1: Fraction of a period:
$T = 1/50 = 0.02$ s, so $\Delta t/T = 0.5$.

Step 2: Phase per period:
A full period is a $2\pi$ phase change.

Step 3: Result:
$0.5\times2\pi = \pi$ rad, option (C).

Final Answer:
The phase change is pi radian. \[ \boxed{\text{(C) }\pi\ \text{rad}} \]