Two light sources of equal amplitudes interfere with each other. Calculate the ratio of maximum and minimum intensities.

Explanation

Let the amplitude be a.
The intensity is, `(I_(max))/(I_(min))=((8)^(2))/((2)^(2))=(64)/(4)=16(or)I_(max):I_(min)=16:1`
Resultant intensity is maximum when, `phi = 0, cos 0 = I, I_(max) prop 4a^(2)`
Resultant amplitude is minimum when,
`phi=pi,cos(pi//2)=0,I_(min)=0`
`I_(max):I_(min)=4a^(2):0`