Question 1

Light of wavelength 500 nm illuminates a round 0.50-mm diameter hole. A screen is placed 6.3 m behind the slit. What is the diameter of the central bright area on the screen?

Accepted Answer

A)  15 mm 
B)  270 μm 
C)  7.7 mm 
D)  3800 μm

Question 2

If an x-ray beam of wavelength 1.4 × 10-10 m makes an angle of 30° with a set of planes in a crystal causing first order constructive interference, what is the plane spacing?

Accepted Answer

A)  0.28 nm 
B)  0.070 nm 
C)  0.32 nm 
D)  0.16 nm 
E)  0.14 nm

Question 3

If the fifth order minimum in the diffraction pattern due to a thin slit is at 40° from the central maximum, at what angle does the first order minimum occur?

Accepted Answer

A)  8.0° 
B)  3.4° 
C)  4.0° 
D)  7.4° 
E)  1.7°

Question 4

A slit of width 0.010 mm has light of frequency 5.0 × 1014 Hz passing through it onto a screen 60 cm away. How wide is the central maximum? (c = 3.00 × 108 m/s)

Accepted Answer

A)  0.12 cm 
B)  7.2 cm 
C)  1.8 cm 
D)  3.6 cm 
E)  0.90 cm

Question 5

A slit of width 2.0 μm is used in a single slit experiment with light of wavelength 650 nm. If the intensity at the central maximum is I0, what is the intensity 10° from the center?

Accepted Answer

A)  0.53I0 
B)  0.030I0 
C)  0.43I0 
D)  0.50I0 
E)  0.35I0

Question 6

If the central maximum in a single slit diffraction pattern has intensity I0, the intensity of the secondary maximum that is nearest to it is closest to

Accepted Answer

A)  0.045I0. 
B)  I0/4. 
C)  I0/2. 
D)  I0. 
E)  2I0.

Question 7

When monochromatic light illuminates a grating with 7000 lines per centimeter, its second order maximum is at 62.4°. What is the wavelength of the light?

Accepted Answer

A)  336 nm 
B)  363 nm 
C)  452 nm 
D)  633 nm 
E)  752 nm

Question 8

If the fifth order minimum in the diffraction pattern of a thin slit is at 40° from the central maximum, what is the highest order minimum in the pattern?

Accepted Answer

A)  6 
B)  11 
C)  8 
D)  7 
E)  9

Question 9

Treat each of your eyes as a circular aperture of diameter 3.5 mm. Light of wavelength 500 nm is used to view two point sources that are 894 m distant from you. How far apart must these two point sources be if they are to be just resolved by your eye? Assume that the resolution is diffraction limited and use Rayleigh's criterion.

Accepted Answer

The answer of Treat each of your eyes as a...

Question 10

A diffraction grating has 450 lines per mm. What is the highest order m that contains the entire visible spectrum from 400 nm to 700 nm?

Accepted Answer

A)  m = 2 
B)  m = 3 
C)  m = 4 
D)  m = 5 
E)  m = 6

Question 11

A certain astronomical telescope has a diameter of 5.60 m. Considering only the limitation due to diffraction, what is the minimum angle of resolution for this telescope at a wavelength of 620 nm?

Accepted Answer

A)  0.111 µrad 
B)  0.311 µrad 
C)  0.270 µrad 
D)  0.135 µrad 
E)  0.405 µrad

Question 12

A diffraction grating has rulings of 890 lines/mm. When white light is incident normally on the grating, what is the longest wavelength that forms an intensity maximum in the fifth order?

Accepted Answer

A)  225 nm 
B)  200 nm 
C)  250 nm 
D)  275 nm 
E)  300 nm

Question 13

A radio telescope 200 m in diameter is used to investigate sources emitting a 21-cm wavelength wave. What is the minimum angular separation of the sources that can be resolved by this system?

Accepted Answer

A)  0.073° 
B)  0.030° 
C)  0.0013° 
D)  0.154° 
E)  0.0026°

Question 14

An 18-mm wide diffraction grating has rulings of 880 lines per mm. Monochromatic light of 590 nm wavelength is incident normally on the grating. What is the largest angle, measured from the central bright spot, at which an intensity maximum is formed?

Accepted Answer

A)  31° 
B)  29° 
C)  27° 
D)  25° 
E)  23°

Question 15

Monochromatic light is incident on a grating that is 75 mm wide and ruled with 50,000 lines. The second-order maximum is seen at 32.5°. What is the wavelength of the incident light?

Accepted Answer

A)  202 nm 
B)  403 nm 
C)  452 nm 
D)  605 nm 
E)  806 nm

Question 16

Monochromatic light of wavelength 500 nm is incident normally on a diffraction grating. If the third-order maximum of the diffraction pattern is observed at 32.0° from the central spot, how many TOTAL number of maxima can be seen?

Accepted Answer

A)  5 
B)  7 
C)  10 
D)  11 
E)  13

Question 17

A metallic sheet has a large number of slits, 5.0 mm wide and 20 cm apart, and is used as a diffraction grating for microwaves. A wide parallel beam of microwaves is incident normally on the sheet. If the microwave wavelength is 6.0 cm, what is the largest angle away from the central maximum at which an intensity maximum occurs.

Accepted Answer

A)  64° 
B)  69° 
C)  74° 
D)  79° 
E)  84°

Question 18

Light of wavelength 687 nm is incident on a single slit 0.75 mm wide. At what distance from the slit should a screen be placed if the second dark fringe in the diffraction pattern is to be 1.7 mm from the center of the diffraction pattern?

Accepted Answer

A)  0.39 m 
B)  0.47 m 
C)  0.93 m 
D)  1.1 m 
E)  1.9 m

Question 19

A diffraction grating has 300 lines per mm. If light of frequency 4.76 × 1014 Hz is sent through this grating, at what angle does the first order maximum occur? (c = 3.00 × 108 m/s)

Accepted Answer

A)  56° 
B)  44° 
C)  22° 
D)  11° 
E)  28°

Question 20

If the headlights on a car are separated by 1.3 m, how far down the road can they be resolved if the angular resolution of the eye is 5.0 × 10-4 rad and the person has excellent vision?

Accepted Answer

A)  1.3 km 
B)  5.0 km 
C)  4.8 km 
D)  0.65 km 
E)  2.6 km

Exam 35: Diffraction

Light of wavelength 500 nm illuminates a round 0.50-mm diameter hole. A screen is placed 6.3 m behind the slit. What is the diameter of the central bright area on the screen?

If an x-ray beam of wavelength 1.4 × 10^-10m makes an angle of 30° with a set of planes in a crystal causing first order constructive interference, what is the plane spacing?

If the fifth order minimum in the diffraction pattern due to a thin slit is at 40° from the central maximum, at what angle does the first order minimum occur?

A slit of width 0.010 mm has light of frequency 5.0 × 10¹⁴Hz passing through it onto a screen 60 cm away. How wide is the central maximum? (c = 3.00 × 10⁸ m/s)

A slit of width 2.0 μm is used in a single slit experiment with light of wavelength 650 nm. If the intensity at the central maximum is I₀, what is the intensity 10° from the center?

If the central maximum in a single slit diffraction pattern has intensity I₀, the intensity of the secondary maximum that is nearest to it is closest to