Question

A plane wave of wavelength 6250 `Å` is incident normally on a slit of width `2 xx 10^(-2)` cm. The width of the principal maximum on a screen distant 50 cm will be
A. `312.5 xx 10^(-3) cm `
B. `312.5 xx 10^(-3)m`
C. `312.5 xx 10^(-2)`m
D. 312.5 xx 10^(-3)`m

Answer 1

Correct Answer - A
Width of central maximum
`=(2Deltalambda)/(a) = (2xx 6250 xx 10^(-10) xx 0.5)/( 2 xx 10^(-4))`
` = 3125 xx 10^(-6) m`
` = 3125 xx 10^(-3) cm`