9702/Oct Nov/12/2016/Q24

A transverse progressive wave of wavelength λ is set up on a stretched string. The graph shows
the variation of displacement y with distance x at a particular instant of time. The displacement
where distance x = λ/8 is y₁.

What are the next two values of x where the displacement y is again equal to y₁?

Solution:

Answer: B

From the figure above, it is very obvious the option C and D are incorrect.

The answer is "B" is because the second value of x must more than λ.

Reference: PYQ - Oct/Nov 2016 Paper 12 Q24