Question

If you shine a laser on two slits with a separation of 0.215 mm, and the diffraction pattern shines on a background 4.90 m away, what is the wavelength of the laser light if the fringes are separated by 1.60 cm

Answer 1

Answer:

$\lambda = 702\ nm$

Explanation:

Given,

slit width, d = 0.215 mm

slit separation, D = 4.90 m

Wavelength of the laser light = ?

Fringe width.$\beta = 1.60\ cm$

Using formula

$\beta =\dfrac{\lambda D}{d}$

$\lambda=\dfrac{\beta d}{D}$

$\lambda=\dfrac{0.016\times 0.215\times 10^{-3}}{4.90}$

$\lambda = 7.02\times 10^{-9}\ m$

$\lambda = 702\ nm$

Wavelength of the laser light = $\lambda = 702\ nm$