Question

If an interference pattern have maximum and minimum intensities in 36 : 1 ratio then what will be the ratio of amplitudes(a) 5 : 7(b) 7 : 4(c) 4 : 7(d) 7 : 5

Answer 1

Correct answer is d 7:5

Answer 2

Answer:

d) 7: 5

Explanation:

The ratio of maximum and minimum intensities = 36:1 ( Given)

When waves interfere, the value at any position and the instant is the sum of the values of the waves. Therefore the maximum amplitude of the waves interference is the sum of the amplitudes and the minimum is the absolute value of their difference. Thus,

Imax/ Imin = ( a1/a2+1)²/  ( a1/a2 -1 )²

Imax/ Imin = a1+ a2/ a1 - a2 = 6

Imax/ Imin = 7: 5

Therefore,  the ratio of amplitudes will be 7: 5.