Question

1. How did Young do his famous double-slit experiment?

A. He used a laser to ensure coherence between the two slits.

B. He used a third slit to produce light that was coherent at the two slits.

C. He later used a gas and did not worry about coherence between the slits.

D. He did not do the experiment at all.

2. In slit problems, when do you make the approximation that the rays come out from the slits parallel to each other?

A. When the slit size and spacing is much smaller than L.

B. When the slit size and spacing is much larger than L.

C. When the part of the diffraction pattern is much smaller than L.

D. When the part of the diffraction pattern is much larger than L.

Answer 1

1)

The rays from the sun passes through a single slit to produce a coherent light, which then passes through another screen with double slits.

Answer is:

B. He used a third slit to produce light that was coherent at the two slits.

2)

When the rays coming out from the slits are parallel to each other, ( ,)

When the distance to the screen is much greater than distance between the slits ,that is

Path difference between the two light rays from the two slits is

Answer is :

A. When the slit size and spacing is much smaller than L.