1. Tardigrade
  2. Question
  3. Physics
  4. A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minima is at a distance of 2.5 mm from the centre of the screen. The width of the slit is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. A parallel beam of light of wavelength $500\, nm$ falls on a narrow slit and the resulting diffraction pattern is observed on a screen $1 \,m$ away. It is observed that the first minima is at a distance of $2.5\, mm$ from the centre of the screen. The width of the slit is

Wave Optics

Solution:

Width of slit, $d = \frac{n\lambda D}{x} $
Here, $n = 1, D = 1 m$,
$ x = 2.5\, mm = 2.5 \times 10^{-3} m $
$ \lambda = 500\, nm = 500\times 10^{-9}m $
$ \therefore d = \frac{1\times 500\times 10^{-9}\times 1}{2.5\times 10^{-3}} $
$=2 \times 10^{-4} m = 0.2 \,mm$