Solveeit Logo
Login

Question

Question: In a young double slit apparatus the screen is rotated by 60º about an axis parallel to the slits. T...

In a young double slit apparatus the screen is rotated by 60º about an axis parallel to the slits. The slits separation is 3 mm, slit to screen distance (at central fringe) is 4m, & wavelength of light is 450 nm. The separation between the 3rd dark fringe on the either side of central fringe is –

A

6 mm

B

8 mm

C

434\sqrt{3}mm

D

232\sqrt{3}mm

Answer

6 mm

Explanation

Solution

Dx at P = dxcos⁡60D\frac{dx\cos 60}{D} = 2.5 l

x = 2.5λ×D×2d\frac{2.5\lambda \times D \times 2}{d} = 5λDd\frac{5\lambda D}{d}

distance between two 3rd dark fringe on either side = 2x = 10λDd\frac{10\lambda D}{d}