In a Young’s double slit experiment, two slits are illuminated with a light of wavelength $800 nm$ . The line joining $A_{1} P$ is perpendicular to $A_{1} A_{2}$ as shown in the figure. If the first minimum is detected at $P$ , the value of slits separation $a$ will be :
The distance of screen from slits $D = 5 cm$ .

Question

In a Young’s double slit experiment, two slits are illuminated with a light of wavelength $800 nm$ . The line joining $A_{1} P$ is perpendicular to $A_{1} A_{2}$ as shown in the figure. If the first minimum is detected at $P$ , the value of slits separation $a$ will be :

The distance of screen from slits $D = 5 cm$ .

TestHub · Accepted Answer

The position of first minima is y = λ D 2 × a ( y is height of the point from the axis passing through the mid-point of A 1 and A 2 ) Since the first minima is in front of the slit as shown in the figure, λ D 2 × a = a 2 ⇒ a = λ D = 800 × 10 - 9 × 5 × 10 - 2 = 2 × 10 - 4 m = 0 . 2 mm

Physics - Wave Optics Question with Solution | TestHub

Options:

Doubts & Discussion