Monochromatic light is passed through double slit and interference pattern is observed on screen 2.5 m away. The separation between slits is 0.5 mm. The first bright fringe is 3.5 mm away from central fringe. The wavelength of light used is

Question

Monochromatic light is passed through double slit and interference pattern is observed on screen 2.5 m away. The separation between slits is 0.5 mm. The first bright fringe is 3.5 mm away from central fringe. The wavelength of light used is (A) 600 nm (B) 500 nm (C) 650 nm (D) 700 nm

Tardigrade Admin · Accepted Answer

y=(λ D/d) Given y=3.5 mm 3.5 × 10-3=(2.5 × λ/0.5 × 10-3) ∴ λ=(3.5 × 10-3 × 0.5 × 10-3/2.5) =700 nm

Q. Monochromatic light is passed through double slit and interference pattern is observed on screen $2.5 m$ away. The separation between slits is $0.5 mm$ . The first bright fringe is $3.5 mm$ away from central fringe. The wavelength of light used is

600 nm

500 nm

650 nm

700 nm

$y = \frac{λ D}{d}$
Given $y = 3.5 mm$
$3.5 \times 1 0^{- 3} = \frac{2.5 \times λ}{0.5 \times 1 0 ^{- 3}}$
$∴ λ = \frac{3.5 \times 1 0 ^{- 3} \times 0.5 \times 1 0 ^{- 3}}{2.5}$
$= 700 nm$

Q. Monochromatic light is passed through double slit and interference pattern is observed on screen 2.5m away. The separation between slits is 0.5mm. The first bright fringe is 3.5mm away from central fringe. The wavelength of light used is