Light of wavelength `lamda` is incident on a slit width d. The resulting diffraction pattern is observed on a screen at a distance D. The linear width of the principal maximum is then equal to the width of the slit if D equals

Options

A. `(d^(2))/(2lamda)`
B. `(d)/(lamda)`
C. `(2lamda^(2))/(d)`
D. `(2lamda)/(d)`

Answer

A

Explanation

The linear width of central principal maximum `=(2lambdaD)/(d)`
If it is equal to width of slit (d), then
`(2lambdaD)/(d)=d "or" D=(d^(2))/(2lambda)`