Question

In a double slit experiment, instead of taking slits of equal widths, one slit is made twice as wide as the other. Then in the interference pattern :

• A. the intensities of both the maxima and minima increase.
• B. the intensity of the maxima increases and the minima has zero intensity.
• C. the intensity of the maxima decreases and that of minima increases.
• D. the intensity of the maxima decreases and the minima has zero intensity.

Answer 1

Answer: (A)

Intensity $\alpha$ width.

	Initially	Final
Maximum	$(\sqrt{I}+\sqrt{I}{)}^2$	$(\sqrt{2I}+\sqrt{I}{)}^2$
Minima	$(\sqrt{1}-\sqrt{I}{)}^2=0$	$(\sqrt{2I}-\sqrt{I}{)}^2$

So intensity of maxima and minima both increases.