9702/Oct Nov/13/2017/Q22

The graph shows how the displacement of a particle in a wave varies with time.

Which statement is correct?
A The wave has a period of 2 s and could be either transverse or longitudinal.
B The wave has a period of 2 s and must be transverse.
C The wave has a period of 4 s and could be either transverse or longitudinal.
D The wave has a period of 4 s and must be transverse.

Solution:

Answer: C

The period of the wave is 4s, so option A and B are incorrect.

The wave could be either transverse or longitudinal because the graph is not represent the actual shape of the longitudinal wave. Because the graph is only represent the displacement of the wave during specific time.

Reference: PYQ - Oct/Nov 2017 Paper 13 Q22