Question

In a single diffraction experiment the width of silt is made double the orginal width how does this affect the size and intensity of central differaction band explaian

Answer 1

The size of the central maximum is given by 2λa where a is the slit width.

It is clear if a is doubled, size of the central maximum is halved. However the intensity changes because of two factors.

One, doubling the width of the slit causes twice the light energy fall on the screen as compared to that with the original width.

Two, the light energy is now squeezed into half of the area on the screen because the size of the central maximum is halved.