Two light beams of intensities in the ratio 25 : 9 are allowed to interfere. The ratio of the intensities of maxima and minima will be

16 : 1

The correct answer is Option (3) → 16 : 1

$I_1 : I_2 = 25 : 9$

$A_1 : A_2 = \sqrt{25} : \sqrt{9} = 5 : 3$

$I_{\max} = (A_1 + A_2)^2 = (5 + 3)^2 = 64$

$I_{\min} = (A_1 - A_2)^2 = (5 - 3)^2 = 4$

$\frac{I_{\max}}{I_{\min}} = \frac{64}{4} = 16$

Final Answer: $16 : 1$