A glass wedge of angle 0.01 radian and μ=1.5 is illuminated by monochromatic light of wavelength 6000 mathringA falling normally on it. At what distance from wedge will 10 text th dark fringe be observed by reflected light?

Question

A glass wedge of angle 0.01 radian and μ=1.5 is illuminated by monochromatic light of wavelength 6000 mathringA falling normally on it. At what distance from wedge will 10 text th dark fringe be observed by reflected light? (A) 0.1 mm (B) 0.2 mm (C) 0.3 mm (D) 0.4 mm

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/24eb8dbaa77680bdfeaac129cc97f7df-.png" /> For dark fringe, 2 μ t=n λ t=(n λ/2 μ)=((10)(6000 × 10-10 m )/2(1.5)) =2 × 10-6 m x=(t/θ)=((2 × 10-6 m )/(0.01 rad )) =2 × 10-4 m =0.2 mm

Q. A glass wedge of angle $0.01$ radian and $μ = 1.5$ is illuminated by monochromatic light of wavelength $6000 \overset{˚}{A}$ falling normally on it. At what distance from wedge will $1 0^{th}$ dark fringe be observed by reflected light?

0.1 mm

0.2 mm

0.3 mm

0.4 mm

For dark fringe, $2 μ t = nλ$
$t = \frac{nλ}{2 μ} = \frac{( 10 ) ( 6000 \times 1 0 ^{- 10} m )}{2 ( 1.5 )}$
$= 2 \times 1 0^{- 6} m$
$x = \frac{t}{θ} = \frac{( 2 \times 1 0 ^{- 6} m )}{( 0.01 r a d )}$
$= 2 \times 1 0^{- 4} m = 0.2 mm$

Q. A glass wedge of angle 0.01 radian and μ=1.5 is illuminated by monochromatic light of wavelength 6000A˚ falling normally on it. At what distance from wedge will 10th dark fringe be observed by reflected light?