Two identical coherent sources are placed on a diameter of a circle of radius R at separation x `(lt lt R)` symmetrical about the center of the circle. The sources emit identical wavelength `lambda` each. The number of points on the circle of maximum intensity is `(x = 5 lambda)`

Options

A. 20
B. 22
C. 24
D. 26

Answer

A

Explanation

Path diff at P is , `Delta = 2(x//2 cos theta) = x cos theta`
For intensity to be maximum
`Delta x = n lambda , x cos theta = n lambda`
`(n lambda)/(x) gt 1 , x = 5 lambda , n= 1,2,3,4,5`
Therefore in all for quadrants these can be 20 maximum