Figure shows a standard two slit arrangement with slits `S_(1), S_(2). P_(1), P_(2)` are the two minima points on either side of P (Figure). At `P_(2)` on the screen, there is a hole and behind `P_(2)` is a second 2-slit arrangement with slits `S_(3), S_(4)` and a second screen behind them.

Options

A. There would be no interference pattern on the second screen but it would be lighted
B. The second screen would be totally dark
C. There would be a single bright point on the second screen
D. There would be a regular two slit pattern on the second screen

Answer

D

Explanation

According to question, there is a hole at point `P_(2)` . From Huygen’s principle, wave will propagate from the sources `S_(1)` and `S_(2)` . Each point on the screen will acts as secondary sources of wavelets. Now, there is a hole at point `P_(2)` (minima). The hole will act as a source of fresh light for the slits `S_(3)` and `S_(4)` . Therefore, there will be a regular two slit pattern on the second screen.