Lecture 14: Chapters 34 (Young’s Double Slit) and Section 35-11 (Polarization)

Gone fishing, 1

To shoot a fish with a gun, how should you aim?

1. aim directly at the image
2. aim slightly above
3. aim slightly below

Gone fishing, 2

To shoot a fish with a laser gun, how should you aim?

1. aim directly at the image
2. aim slightly above
3. aim slightly below

Superposition

Phase difference

The two waves shown are

1. out of phase by $\pi$.

2. out of phase by $\pi / 2$.

3. out of phase by $\pi / 4$.

4. in phase.

Young’s double slit experiment

An interference pattern is seen from two slits. Now, cover one slit with glass, introducing a phase difference of $\pi$ (180$^\circ$; half wavelength) at the slits. How is the pattern altered?

1. pattern vanishes.
2. pattern expands.
3. bright and dark spots are interchanged.
4. no change at all.

Young’s double slit experiment

In a double slit experiment, if the wavelength of the light is increased, the interference pattern will

1. spread out.
2. shrinks together.
3. stays the same.
4. disappears.