Optics Question 1067
Question: In Young’s double slit experiment, if the slit widths are in the ratio 1 : 9, then the ratio of the intensity at minima to that at maxima will be
[MP PET 1987]
Options:
A) 1
B) 1/9
C) 1/4
D) 1/3
Show Answer
Answer:
Correct Answer: C
Solution:
Slit width ratio = 1 : 9 Since slit width ratio is the ratio of intensity and intensity $ \propto $ (amplitude)2
$ \therefore I _{1}:I _{2}=1:9 $
$ \Rightarrow a _{1}^{2}:a _{2}^{2}=1:9\Rightarrow a _{1}:a _{2}=1:3 $
$ {I _{\max }}={{(a _{1}+a _{2})}^{2}},\ \ {I _{\min }}={{(a _{1}-a _{2})}^{2}}\Rightarrow \frac{{I _{\min }}}{{I _{\max }}}=\frac{1}{4} $
