Question

What will be the angular width of central maxima in Fraunhoffer diffraction when light of wavelength $6000\mathring{A}$ is used and slit width is $12\times {10}^{-5}cm$.

• A. $2rad$
• B. $3rad$
• C. $1rad$
• D. $8rad$

Answer 1

Answer: (C)

$1rad$

Given,

$\lambda =6000\mathring{A}$

$d=12\times {10}^{-5}cm$

The angular width of central maxima in Fraunhoffer diffraction is given by,

full angular width $=\frac{2\lambda }{d}$

$=\frac{2\times 6000\times {10}^{-10}}{12\times {10}^{-5}}$

$=1rad$