Question

Yellow light is used in a single slit diffraction experiment with a slit of width $0.6mm$. If yellow light is replaced by $X-$ rays, then the observed pattern will reveal :

• A. more number of fringes
• B. less number of fringes
• C. no diffraction pattern
• D. that the central maximum is narrower

Answer 1

The correct option is D that the central maximum is narrower

As x-rays has more energy than yellow light it has less wavelength than yellow light.
The angular size of the central maxima is
$\theta =\frac{n\lambda }{a}$ where, n is integer $(\ne 0)$ $\lambda$ is wavelength of light used a is slot width.
So, as '$\lambda$' is decreased by using x-rays in place of yellow light the central maxima becomes narrower.