Question 1

Using a Michelson interferometer and a light source of 400 nm, a change from bright to dark indicates a change in the difference of arm lengths of

Accepted Answer

A)  2.0 × 10-4 mm. 
B)  4.0 × 10-4 mm. 
C)  3.0 × 10-4 mm. 
D)  1.0 × 10-4 mm. 
A)  2.0 × 10-4 mm. 
B)  4.0 × 10-4 mm. 
C)  3.0 × 10-4 mm. 
D)  1.0 × 10-4 mm.

Question 2

Two coherent waves interfere constructively. One wave has amplitude 8A0 and the other has amplitude 6A0. The amplitude of the superposed wave is

Accepted Answer

A)  6A0. 
B)  8A0. 
C)  10A0. 
D)  14A0. 
E)  2A0. 
A)  6A0. 
B)  8A0. 
C)  10A0. 
D)  14A0. 
E)  2A0.

Question 3

For an angle of 10 degrees, what is the percent difference between sin θ and θ in radians?

Accepted Answer

A)  0.1% 
B)  0.3% 
C)  0.5% 
D)  0.7% 
E)  more than 1% 
A)  0.1% 
B)  0.3% 
C)  0.5% 
D)  0.7% 
E)  more than 1%

Question 4

If two coherent waves, one with intensity 8.0 I0 and the other with intensity 4.0 I0, undergo destructive interference, what is the resulting intensity?

Accepted Answer

A)  4.0 I0 
B)  6.0 I0 
C)  −4.0 I0 
D)  1.9 I0 
E)  0.69 I0 
A)  4.0 I0 
B)  6.0 I0 
C)  −4.0 I0 
D)  1.9 I0 
E)  0.69 I0

Question 5

In a Young's double-slit experiment, a fifth-order maximum occurs at an angle of 1.422°. If the screen is 3.90 m from the slits and the slit separation is 0.135 mm, what wavelength is being used?

Accepted Answer

A)  335 nm 
B)  670 nm 
C)  476 nm 
D)  589 nm 
E)  690 nm 
A)  335 nm 
B)  670 nm 
C)  476 nm 
D)  589 nm 
E)  690 nm

Question 6

A grating with 8000 slits over 2.54 cm is illuminated by light of a wavelength of 546 nm. What is the angle for the third-order maximum?

Accepted Answer

A)  31.1° 
B)  15.1° 
C)  26.3° 
D)  10.5° 
A)  31.1° 
B)  15.1° 
C)  26.3° 
D)  10.5°

Question 7

A grating is made with 600 slits per millimeter. What is the slit separation?

Accepted Answer

A)  600 nm 
B)  1.67 × 10-6 m 
C)  3.33 × 10-6 m 
D)  160 pm 
E)  916 nm 
A)  600 nm 
B)  1.67 × 10-6 m 
C)  3.33 × 10-6 m 
D)  160 pm 
E)  916 nm

Question 8

A Young's double-slit experiment is performed and then repeated after moving the screen to three times the previous distance from the slits. What happens to the angular separation (as measured from the slits) of the fourth-order maxima?

Accepted Answer

A)  There is no change. 
B)  It becomes one-third the original value. 
C)  It becomes four times the original value. 
D)  It triples. 
E)  It increases by a factor of 2.25. 
A)  There is no change. 
B)  It becomes one-third the original value. 
C)  It becomes four times the original value. 
D)  It triples. 
E)  It increases by a factor of 2.25.

Question 9

In a two-slit experiment, there are 11 bright fringes within the central diffraction maximum (on each side, the first diffraction minimum coincides with where the next interference bright fringe would be). What is the ratio of the slit width to the slit separation?

Accepted Answer

A)  5 
B)  1/6 
C)  1/5 
D)  6 
A)  5 
B)  1/6 
C)  1/5 
D)  6

Question 10

A Michelson interferometer is set up for microwaves. Initially the reflectors are placed so the detector reads a maximum. When one of the reflectors is moved 12 cm, the reading goes from a maximum to a minimum and back to maximum six times. What is the wavelength of the microwaves?

Accepted Answer

A)  0.5 cm 
B)  4 cm 
C)  1 cm 
D)  2 cm 
A)  0.5 cm 
B)  4 cm 
C)  1 cm 
D)  2 cm

Question 11

How far away can two point sources of light of wavelength 500 nm be, if they are just resolvable in a telescope with an aperture width of 1.5 cm?

Accepted Answer

A)  25 km 
B)  12 km 
C)  90 m 
D)  12 m 
E)  more information is needed 
A)  25 km 
B)  12 km 
C)  90 m 
D)  12 m 
E)  more information is needed

Question 12

If the two second-order maxima (m = ±2) are separated by 2.0 cm on the screen in a double-slit experiment, what is the separation of the m = ±3 maxima? Assume the angles are very small.

Accepted Answer

A)  1.5 cm 
B)  2.0 cm 
C)  2.5 cm 
D)  3.0 cm 
E)  3.5 cm 
A)  1.5 cm 
B)  2.0 cm 
C)  2.5 cm 
D)  3.0 cm 
E)  3.5 cm

Exam 25: Interference and Diffraction

Using a Michelson interferometer and a light source of 400 nm, a change from bright to dark indicates a change in the difference of arm lengths of

Two coherent waves interfere constructively. One wave has amplitude 8A0 and the other has amplitude 6A0. The amplitude of the superposed wave is

For an angle of 10 degrees, what is the percent difference between sin θ and θ in radians?

If two coherent waves, one with intensity 8.0 I0 and the other with intensity 4.0 I0, undergo destructive interference, what is the resulting intensity?

In a Young's double-slit experiment, a fifth-order maximum occurs at an angle of 1.422°. If the screen is 3.90 m from the slits and the slit separation is 0.135 mm, what wavelength is being used?

A grating with 8000 slits over 2.54 cm is illuminated by light of a wavelength of 546 nm. What is the angle for the third-order maximum?

A grating is made with 600 slits per millimeter. What is the slit separation?

A Young's double-slit experiment is performed and then repeated after moving the screen to three times the previous distance from the slits. What happens to the angular separation (as measured from the slits) of the fourth-order maxima?

In a two-slit experiment, there are 11 bright fringes within the central diffraction maximum (on each side, the first diffraction minimum coincides with where the next interference bright fringe would be). What is the ratio of the slit width to the slit separation?

A Michelson interferometer is set up for microwaves. Initially the reflectors are placed so the detector reads a maximum. When one of the reflectors is moved 12 cm, the reading goes from a maximum to a minimum and back to maximum six times. What is the wavelength of the microwaves?

How far away can two point sources of light of wavelength 500 nm be, if they are just resolvable in a telescope with an aperture width of 1.5 cm?

If the two second-order maxima (m = ±2) are separated by 2.0 cm on the screen in a double-slit experiment, what is the separation of the m = ±3 maxima? Assume the angles are very small.

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Filters

Two coherent waves interfere constructively. One wave has amplitude 8A₀ and the other has amplitude 6A₀. The amplitude of the superposed wave is

If two coherent waves, one with intensity 8.0 I₀ and the other with intensity 4.0 I₀, undergo destructive interference, what is the resulting intensity?