Q. The maximum number of possible interference maxima for slit-separation equal to twice the wavelength in Young’s double-slit experiment is
A) Infinite
B) Five
C) Three
D) Zero
Explanation
(b) For maxima $\mathrm{\Delta} = d\sin\theta = n\lambda$
$\Rightarrow 2\lambda\sin\theta = n\lambda \Rightarrow \sin\theta = \frac{n}{2}$
Since value of $\sin\theta$ can not be greater 1
$\therefore n = 0,\ 1,\ 2$
Therefore only five maximas can be obtained on both side of the screen
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.