The rope shown at an instant is carrying a wave travelling towards right, created by a source vibrating at a frequency f. Consider the following statements
I. the speed of the wave is 4 f × ab
II. the medium at a will be in the same phase as d after 4/3f s
III. the phase difference between b and e is 3π/2
Which of these statements are correct ?
(a) I, II and III
(b) II only
(c) I and III
(d) III only
