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

Answer 1

Answer: (A)

$I_{\min } \propto(a-a)^{2}$
$I_{\min }' \propto(2 a-a)^{2}$
Clearly, the intensity of minima increases.
Again $I_{\max } \propto(a+a)^{2}$
$I_{\max }' \propto(2 a+a)^{2}$
Clearly, the intensity of maxima increases.