Question

In Young's double slit experiment, if the distance between the slits is doubled while keeping the wavelength and the distance to the screen constant, the fringe spacing will:

Hint:

Fringe spacing in double slit experiments is inversely proportional to the slit separation.

Answer 1

The fringe spacing (\( \beta \)) in Young's double slit experiment is calculated using:

\[ \beta = \frac{\lambda L}{d} \]

Variables are defined as:

• \( \lambda \) = wavelength of light
• \( L \) = distance from slits to screen
• \( d \) = distance between slits

When \( d \) is doubled to \( d' = 2d \), with \( \lambda \) and \( L \) unchanged:

\[ \beta' = \frac{\lambda L}{2d} = \frac{\beta}{2} \]

Consequently, the fringe spacing is reduced by half.