Question

Which point on the wave diagram below are 90° out of phase with each other?

Answer 1

The answer is b and c because both of them are 90 degrees apart and the make a right angle

Answer 2

Answer:

4.  D and E

Explanation:

As we know that the relation between phase difference and path difference is given below

$\delta \phi = \frac{2\pi}{\lambda} \delta x$

now we have to find the distance of two points which are out of phase by 90 degree

so here we will have

$\frac{\pi}{2} = \frac{2\pi}{\lambda} \delta x$

so from above we have

$\delta x = \frac{\lambda}{4}$

so the distance between the points will be 1/4 times of wavelength

so here correct answer is

4. D and E