### Short Answer

### 17.1 Understanding Diffraction and Interference

- The bands would be closer together.
- The bands would spread farther apart.
- The bands would remain stationary.
- The bands would fade and eventually disappear.

- The width of the spaces between the bands will remain the same.
- The width of the spaces between the bands will increase.
- The width of the spaces between the bands will decrease.
- The width of the spaces between the bands will first decrease and then increase.

- $667\phantom{\rule{thinmathspace}{0ex}}\text{nm}$
- $471\phantom{\rule{thinmathspace}{0ex}}\text{nm}$
- $333\phantom{\rule{thinmathspace}{0ex}}\text{nm}$
- $577\phantom{\rule{thinmathspace}{0ex}}\text{nm}$

What is the longest wavelength of light passing through a single slit of width 1.20 Î¼m for which there is a first-order minimum?

- 1.04 Âµm
- 0.849 Âµm
- 0.600 Âµm
- 2.40 Âµm

### 17.2 Applications of Diffraction, Interference, and Coherence

- A diffraction grating is a large collection of evenly spaced parallel lines that produces an interference pattern that is similar to but sharper and better dispersed than that of a double slit.
- A diffraction grating is a large collection of randomly spaced parallel lines that produces an interference pattern that is similar to but less sharp or well-dispersed as that of a double slit.
- A diffraction grating is a large collection of randomly spaced intersecting lines that produces an interference pattern that is similar to but sharper and better dispersed than that of a double slit.
- A diffraction grating is a large collection of evenly spaced intersecting lines that produces an interference pattern that is similar to but less sharp or well-dispersed as that of a double slit.

Suppose pure-wavelength light falls on a diffraction grating. What happens to the interference pattern if the same light falls on a grating that has more lines per centimeter?

- The bands will spread farther from the central maximum.
- The bands will come closer to the central maximum.
- The bands will not spread farther from the first maximum.
- The bands will come closer to the first maximum.

How many lines per centimeter are there on a diffraction grating that gives a first-order maximum for 473 nm blue light at an angle of 25.0Â°?

- 529,000 lines/cm
- 50,000 lines/cm
- 851 lines/cm
- 8,934 lines/cm

What is the distance between lines on a diffraction grating that produces a second-order maximum for 760-nm red light at an angle of 60.0Â°?

- 2.28 Ã— 10
^{4}nm - 3.29 Ã— 10
^{2}nm - 2.53 Ã— 10
^{1}nm - 1.76 Ã— 10
^{3}nm