Ch 17: Wave Optics

Question 1

When light travels (more slowly than in a vacuum) through a transparent medium, the wavelength inside the material decreases, but the ________ doesn’t change.

Answer 1

frequency

Question 2

The spreading of diffraction becomes noticeable only when an opening or object is “narrow”, comparable in size to the __________ of the wave.

Answer 2

wavelength

Question 3

The index of refraction is…

Answer 3

the speed of light in a vacuum (c) / the speed of light in the medium (v)

Question 4

Given the following problem, what equation is needed in order to solve it?

A 1.0 cm-wide diffraction grating has 1000 slits. It is illuminated by light of wavelength 550 nm. What are the angles of the 1st two diffraction orders?

Answer 4

d sin θ = mλ

d represents the slit spacing, m represents the order of diffraction, and λ is the wavelength

Question 5

What is the condition for constructive interference with either 0 or 2 reflective phase changes?

Answer 5

2t = m (λ/n)

Question 6

What is the condition for destructive interference with only 1 reflective phase change?

Answer 6

2t = m (λ/n)

Question 7

What is the condition for destructive interference with either 0 or 2 reflective phase changes?

Answer 7

2t = (m + 1/2)(λ/n)

Question 8

What is the condition for constructive interference with only 1 reflective phase change?

Answer 8

2t = (m + 1/2)(λ/n)

Question 9

Single slit diffraction:

Each point on a wave front is a source of spherical wavelets. The superposition of these wavelets products the diffraction pattern on the screen.
The constructive interference between these wavelets produces the _______ _________ of the diffraction pattern at θ = 0.

Answer 9

central maximum

Question 10

What is the condition for dark fringes in a single-slit diffraction with slit width a?

Answer 10

a sin θ

Question 11

What is the formula for percent error?

Answer 11