Question

If two sources of intensifies $I_0$ each have a randomly varying phase difference ф, the resultant intensity at centre of screen will be :

• A. $I_0$/2
• B. 2/$I_0$
• C. 2$I_0$
• D. $I_0$/√2

Answer 1

Answer: (C)

2$I_0$

Answer 2

The correct answer is (C): 2$I_0$

As we know the phase difference is varying, then the waves are said to be incoherent. So, the intensity of resultant wave is the sum of intensities of each wave is 2$I_0$.