Q. The condition for diffraction of $m$ th order minima is
A) $d\sin{\theta_{m} = m\lambda,m = 1,\ 2,\ 3,\ \ldots}$
B) $d\sin{\theta_{m} = \frac{m\lambda}{2},m = 1,\ 2,\ 3,\ \ldots}$
C) $d\sin{\theta_{m} = (m + 1)\frac{\lambda}{2},m = 1,\ 2,\ 3,\ \ldots}$
D) $d\sin{\theta_{m} = (m - 1)\frac{\lambda}{2},m = 1,\ 2,\ 3,\ \ldots}$
Explanation
(a) For obtaining mth secondary minima at a point on screen, path difference between the diffracted waves $\mathrm{\Delta} = d\sin\theta_{m} = \pm m\lambda$
Where, m = 1, 2, 3, …..
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.