# Wave Optics: Interference and Diffraction

1.A circular diffraction pattern is formed on a faraway screen.

(a) By what factor will the width of the central maximum change if the wavelength is doubled?

(a) 4

(b) 2

(c) 1 (no change)

(d) 1/2

(e) 1/4

(b) By what factor will the area of the central maximum change if the slit width is doubled?

(a) 4

(b) 2

(c) 1 (no change)

(d) 1/2

(e) 1/4

2. Consider a Young's two-slit experiment in which the wavelength of light is 38% smaller than the distance between

the slits.

(a) How many complete dark fringes would be seen on a distant screen? (Assume for all these questions that

the screen is as large as it needs to be.)

(a) 0

(b) 1

(c) 2

(d) 3

(e) 4

(f) 5

(b) How many total interference maxima would be seen on a distant screen?

(a) 0

(b) 1

(c) 2

(d) 3

(e) 4

(f) 5

(c) Now suppose that the wavelength of light is 134% larger than the slit separation. How many complete dark

fringes would be seen on a distant screen?

(a) 0

(b) 1

(c) 2

(d) 3

(e) 4

(f) 5

#### Solution Summary

Two problems with parts about the interference and diffraction are solved.