Question

Statement I: In calculating the disturbance produced by a pair of superimposed incoherent wave trians, you can add their intensities.
Statement II: `I_(1) + I_(2) + 2 sqrt(I_(1) I_(2)) cos delta`. The average value of `cos delta = 0` for incoherent waves.
A. Statement-1 is true Statemetnt-2 is True,Statement -2 is a correct explanation for statement -1.
B. Statement-1 is true Statemetnt-2 is True,Statement -2 is NOT a correct explanation for statement -1.
C. Statement -1 is true,statement -2 is false
D. Statement -1 is False ,statement -2 is True.

Answer 1

Correct Answer - A
Average value of `(cos delta=underset(t)overset(t=T)intcos(phi_1-phi_2)dt)/T=0` Here `phi_1` and `phi_2` are constantly randomly, fluctuating phases of the two wave trains and integral is taken over a long time (relative to periods of the individual waves).