What is the ratio of intensity of bright spot to that of a dark spot in an interference pattern, if the ratio of intensities of the two interfering waves is 3:5 ? 

Asked by nayonikamenon15 | 11th Jan, 2016, 12:37: AM

Expert Answer:

Dear nayonikamenon15@gmail.com

Thanks for asking us a question in Ask the Expert section of TopperLearning.com.

We have not understood the query that you have posted. 
You have given the ratio of intensities. However, the ratio of amplitude must also be specified.
Considering that the amplitude ratio of two sources producing interefernce is 3:5, such that

.begin mathsize 12px style straight A subscript 1 over straight A subscript 2 equals 3 over 5 or space straight A subscript 1 equals 3 over 5 straight A subscript 2 space...... left parenthesis Equation space 1 right parenthesis We space know space that space straight I subscript max over straight I subscript min equals open parentheses straight A subscript 1 plus straight A subscript 2 close parentheses squared over open parentheses straight A subscript 1 minus straight A subscript 2 close parentheses squared Solving space the space above space equation space in space terms space of space straight A subscript 2 space using space euation space 1 comma space we space get straight I subscript max over straight I subscript min equals open square brackets 2 close square brackets squared over open square brackets 8 close square brackets squared equals 1 over 16 end style
 

Regards

Topperlearning Team

Answered by Yashvanti Jain | 12th Jan, 2016, 12:38: PM