Question

How to increase the widths of the fringes in the diffraction pattern that appears on the screen in a double-slit interference experiment with light?

• A. Use light of a shorter wavelength
• B. Move the screen closer to the slits
• C. Move the slits closer together
• D. Use light with a lower wave speed
• E. Increase the intensity of the light

Answer 1

Answer: (C)

Move the slits closer together

We know the fringe width $\beta =\frac{D\lambda }{d}$

where$D=$ distance between slits and screen

$\lambda =$ wavelength of light used

$d=$ distance between two slits

by above formula $\beta \propto \frac{1}{d}$

therefore fringe width increases when distance between two slits will decrease or we can say that we move the slits closer together.