Question
Physics Question on Electromagnetic waves
Two waves having intensities in the ratio of 9 : 1 produce interference. The ratio of maximum to minimum intensity is equal to
A
10:08
B
9 : I
C
4:01
D
2 : l
Answer
4:01
Explanation
Solution
\hspace30mm \frac{I_1}{I_2} = \frac{a_1^2}{a_2^2} = \frac{9}{1} \Rightarrow \hspace20mm \frac{a_1}{a_2} = \sqrt{\frac{9}{1}} \Rightarrow \hspace20mm \frac{a_1}{a_2} = \frac{3}{1} \therefore \hspace20mm \frac{I_{max}}{I_{min}} = \frac{(a_1 + a_2)^2}{(a_1 - a_2)^2} \hspace30mm = \frac{(3 + 1)^2}{(3 - 1)^2} \hspace30mm = \frac{(3)^2}{(2)^2} = \frac{16}{4} \hspace30mm = \frac{4}{1} Thus, \hspace20mm I_{max} : I_{min} = 4 : 1