Question

Light passes through a 10-µm-wide slit and is viewed on a screen 1 m behind the slit. If the width of the slit is narrowed, the band of light on the screen will

A. Become narrower.
B. Become wider.
C. Stay about the same.

Answer 1

Option B is correct (Become wider)

Step-by-step explanation:

Option B is correct (Become wider)

According to single slit formula for central bright maximum:

`d=(2\lambda L)/(a)`

where:

d is the width for central bright maximum

λ is the wavelength

L is the distance between slit and screen

a is the width of slit

Now keeping L and λ constant:

d=C/a

where:

C is constant=2λL

d∝1/a

Width of central bright maximum is inversely proportional to width of slit.

So,If the width of the slit is narrowed, the band of light on the screen will become wider