Question

A laser of wavelength 633 (nm) illuminates two slits separated by 0.4 (mm). A screen is located 2 (m) from the slits. What is the distance on the screen from the central maxima to the 2nd Order bright line? a) 0.4 (mm) b) 0.8 (mm) c) 3.15 (mm) d) 6.3 (mm)

Answer 1

Answer:

The distance on the screen from the central maxima to the second order bright line is 6.33 mm

Explanation:

It is given that,

Wavelength of lase light, $\lambda=633\ nm=633\times 10^{-9}\ m$

Separation between slits, d = 0.4 mm = 0.0004 m

Distance between screen and slits, D = 2 m

We need to find the distance on the screen from the central maxima to the 2nd Order bright line. It can be calculated using :

$Y=\dfrac{n\lambda D}{d}$

n = 2

$Y=\dfrac{2\times 633\times 10^{-9}\times 2}{0.0004}$    

Y = 0.00633 m

or

Y = 6.33 mm

So, the distance on the screen from the central maxima to the second order bright line is 6.33 mm. Hence, this is the required solution.