Question

In a double slit interference experiment, the maximum intensity of light would be _____ the maximum intensity of a single slit experiment.

• A. same as
• B. twice
• C. four times
• D. half

Answer 1

Answer: (C)

$\because$ in the double-slit experiment
$I_{net}=I_1+I_2+2\sqrt{I_1{I}_2}cos\varphi$
When $I_1=I_2$ and $cos\varphi =+1$
we get $I_{max}=4I_1$
$\therefore$ maximum intensity in the double-slit interference
$=4$ (maximum intensity of single slit experiment)