CHECKPOINT 4 (page 904)
Four pairs of polarizing sheets are placed in the
path of initially unpolarized light, with the polarizing
direction of each sheet indicated by the dashed line.
Ranks the pairs according to the fraction of the
initial intensity that they pass.
PHY2049: Chapter 33
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(continued)
‹ A:
b>c>d>a
‹ B: a > d > b > c
‹ C: c > b > d > a
‹ D: d > c > b > a
‹ E: a > b > d > c
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Quiz
0°
0°
90°
45°
90°
45°
(b)
(a)
• Initially unpolarized light is sent into a set of three
polarizing sheets, either a or b. Which set lets more
light through?
a (b completely blocks light.)
• What fraction of the light’s initial intensity is
transmitted?
1/8
PHY2049: Chapter 33
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CHECKPOINT
(a)
(b)
Light travels from a medium whose index of refraction is n1
into another medium whose index of refraction n2. In which
of the two cases is n2 larger than n1?
a
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Chromatic dispersion
White
light
Violet
Red
Prisms have double reflections and limited resolution. To study a light spectrum,
diffraction gratings (see Chapter 36) are used instead of prisms. See a demo in
the lobby.
PHY2049: Chapter 33
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Total Internal Reflection
n2
n1
For a total reflection to occur,
n1 has to be larger than n2.
PHY2049: Chapter 33
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Quiz
radius
n2 ≈ 1
n1 = 1.33
A point source of light is located 3 m below the
body of water. Find the diameter of the circle at the
surface through which light emerges from the
water.
θ = 48.8° 2r = 6.84 m
PHY2049: Chapter 33
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