The interference pattern is obtained with two coherent light sources of intensity ratio 4 : 1 . And the ratio I max + I min I max - I min is 5 x . Then, the value of x will be equal to :

Step-by-step solution

The ratio of the intensities is I 1 I 2 = 4 1    After taking square root of above equation on both sides, we get, I 1 I 2 = 2 1 Apply componendo and dividendo, ⇒ I 1 + I 2 I 1 - I 2 = 2 + 1 2 - 1 = 3 1 ⇒ I 1 + I 2 I 1 - I 2 2 = I max I min = 9 1 ⇒ I m a x + I m i n I m a x - I m i n = 10 8 = 5 4 Therefore, the answer is 4 .