Question

The rope shown at an instant is carrying a wave travelIing towards right created source vibrating at a frequency n consider the following statement:
(i) The speed of the wave is $4n\times ab$
(ii) The medium at a will be in the same phase as d after $\frac{4}{3n}$ sec
(iii) the phase difference between b and e is $\frac{3\pi }{2}$
Which of these statement(s) is/are correct?

• A. (iii) only
• B. (i) and (iii) only
• C. (ii) only
• D. (ii), (i), (iii)

Answer 1

The correct option is B (i) and (iii) only

Statement (iii) is only correct as the phase differences between points band c, c and d and d and e are $\frac{\pi }{2}$ each
$\therefore$ the phase difference between b and e
$\frac{\pi }{2}+\frac{\pi }{2}+\frac{\pi }{2}=\frac{3\pi }{2}$