Question

Two coherent sources of different intensities send waves that interfere.The ratio of maximum to minimum intensity is 25. The intensity ratio of the sources is

Answer 1

Hello friend,

◆ Answer-

I1/I2 = 9/4

◆ Explanation -

# Given-

Imax/Imin = 25

# Solution-

Intensity of light wave is directly proportional to amplitude.

I ∝ a^2

I1/I2 = (a1/a2)^2 ...(1)

Also, ratio of maximum to minimum intensity is calculated by-

Imax / Imin = (a1+a2)^2 / (a1-a2)^2

25 = (a1+a2)^2 / (a1-a2)^2 ...(2)

Solving this you'll get -

a1/a2 = 3/2

Putting this in eqn (1),

I1/I2 = (3/2)^2

I1/I2 = 9/4

Therefore, ratio of intensity of sources is 9/4.

Hope this helps you...