Question

In the yonug's double slit experiment the central maxima is observed to be $I_0.$ If one of the slits is covered, the intensity at the central maxima will become:

• A. $I_0/2$
• B. $I_0/\sqrt{2}$
• C. $I_0/4$
• D. $I_0$

Answer 1

The correct option is C $I_0/4$

Given that,

Intensity of central maxima $=I_0$

we know

$I_1+I_2+2\sqrt{I_1{I}_2}\cos \theta$

For maxima

$\cos \theta =1$

$\begin{array}{cc}& \text{Inet}=I_1+I_2+2\sqrt{I_1{I}_2}\times 1\\ \text{Let sits are ldentical}& \\ & I_1=I_2=I\\ I_0& =I+I+2\sqrt{II}\end{array}$

$\begin{array}{c}\text{if one slit is covered then intensity of that}\\ \text{slit become zero}\\ \text{Let}{I}_2\text{is covered}\\ \text{Now New Inet will be}\\ \text{From (i) and (ii)}\\ {\left(I_0\right)}_{\text{new}}=\frac{I_0}{4}\end{array}$