Figure 10.2 shows a standard two slit arrangement with slits S1, S2 . P1, P2 are the two minima points on either side of P (Fig. 10.2).
At P2 on the screen, there is a hole and behind P2 is a second 2- slit arrangement with slits S3, S4 and a second screen behind them.
1
There would be no interference pattern on the second screen but it would be lighted.
2
The second screen would be totally dark
3
There would be a single bright point on the second screen.
4
There would be a regular two slit pattern on the second screen.