Question

Snapshot for a rope shown, at an instant is carrying a travelling wave towards right, created by source vibrating with the frequency "n". Then,

• A. the speed of the wave is (4 n) (distance ab)
• B. the particle at point a will be in the present phase of d after $\frac{4}{3n}$ sec.
• C. the phase difference between b and e is $\frac{3\pi }{2}$
• D. the wave is harmonic

Answer 1

Answer: (A), (C), (D)

The correct options are
A the speed of the wave is (4 n) (distance ab)
C the wave is harmonic
D the phase difference between b and e is $\frac{3\pi }{2}$

As it is a sinusoidal curve so wave is obviously harmonic,
Now $V=\gamma \lambda ,$ where $\gamma$ is frequency
$=n\left(4ab\right)$
$=4n\left(distanceab\right)$
Phase delay of $d=\frac{3\lambda /4}{v}=\frac{\frac{3}{4}\left(4ab\right)}{4n\left(ab\right)}=\frac{3}{4n}$
Phase difference between b and e $=3\times \frac{\pi }{2}=\frac{3\pi }{2}$