Transcript B) a bright spot appears at the half-wave point

Chapter 16
Pretest
Interference and
Diffraction
1. When monochromatic light is
reflected from a thin transparent film,
A) constructive interference occurs
when the film is one-half wavelength
thick,
B) a bright spot appears at the halfwave point,
C) destructive interference occurs when
the film is one-fourth wavelength thick,
D) a dark spot appears at the half-wave
point.
1. When monochromatic light is
reflected from a thin transparent film,
A) constructive interference occurs
when the film is one-half wavelength
thick,
B) a bright spot appears at the halfwave point,
C) destructive interference occurs when
the film is one-fourth wavelength thick,
D) a dark spot appears at the half-wave
point.
2. For a thin film bounded on
both sides by a medium of lower
index of refraction, maximum
constructive interference occurs
if the optical path difference is:
A) l/4,
B) l/2,
C) ¾ l,
D) l.
2. For a thin film bounded on
both sides by a medium of lower
index of refraction, maximum
constructive interference occurs
if the optical path difference is:
A) l/4,
B) l/2,
C) ¾ l,
D) l.
3. For high resolution in
optical instruments, the angle
between resolved objects
should be:
A) as small as possible,
B) as large as possible,
C) 1.22°,
D) 45°.
3. For high resolution in
optical instruments, the angle
between resolved objects
should be:
A) as small as possible,
B) as large as possible,
C) 1.22°,
D) 45°.
4. Interference effects observed in
the early 1800s were instrumental
in supporting a concept of the
existence of which property of light?
A. polarization
B. particle nature
C. wave nature
D. electromagnetic character
4. Interference effects observed in
the early 1800s were instrumental
in supporting a concept of the
existence of which property of light?
A. polarization
B. particle nature
C. wave nature
D. electromagnetic character
5. For stable interference
to occur, the phase
difference must be:
A. V/C
B. cl
C. ½ l
D. constant
5. For stable interference
to occur, the phase
difference must be:
A. V/C
B. cl
C. ½ l
D. constant
6. At the first dark band in a
single-slit interference pattern,
the path lengths of selected
pairs of wavelets differ by:
A. one wavelength
B. more than one wavelength
C. one-half wavelength
D. less than half of one
wavelength
6. At the first dark band in a
single-slit interference pattern,
the path lengths of selected
pairs of wavelets differ by:
A. one wavelength
B. more than one wavelength
C. one-half wavelength
D. less than half of one
wavelength
7. Which of the following is a
device that produces an
intense, nearly parallel beam
of coherent light?
A. spectroscope
B. telescope
C. laser
D. diffraction grating
7. Which of the following is a
device that produces an
intense, nearly parallel beam
of coherent light?
A. spectroscope
B. telescope
C. laser
D. diffraction grating
1. Why are the
interference effects
observed in light
reflected by thin films
the reverse of those
normally expected?
There is a phase
inversion where the
medium beyond is
of a higher index of
refraction.
2. Calculate to the nearest
0.1° the diffraction angle of
the first-order image
produced by a grating ruled
5000 lines/cm illuminated with
monochromatic light having a
wavelength of 295
nanometers.
l = d sin q/m
295 X 10-9 = (1/5000)(1/100) sinq/1
q = 8.5º
3. The angle between the first
order maximum and zeroth
order maximum for
monochromatic light of
2300 nm is 27°. Calculate the
number of lines per
centimeter on this grating.
l = d sin q/m
2300 X
-9
10
= d sin27º /1
d = 5.066 x
1/(5.066 x
-6
10 m/line
-6
10 )(1/100)
1974 lines/cm
4. Monochromatic light from a
helium-neon laser (l = 632.8 nm)
shines at a right angle onto the
surface of a diffraction grating
that contains 630,692 lines/m.
Find the angles at which one
would observe the first-order and
second-order maxima.
l = d sin q/m
632.8 X 10-9 = 1/(630,692) sinq/1
q = 23.5º
l = d sin q/m
632.8 X 10-9 = 1/(630,692) sinq/2
q = 53.0º