Chapter 24 Sample Multiple Choice Problems

1.       What principle is responsible for light spreading as it passes through a narrow slit?

a.        refraction

b.        polarization

c.        diffraction

d.        interference

2.       What principle is responsible for alternating light and dark bands when light passes through two
or more narrow slits?

a.        refraction

b.        polarization

c.        diffraction

d.        interference

3.       What principle is responsible for the fact that certain sunglasses can reduce glare from reflected
surfaces?

a.        refraction

b.        polarization

c.        diffraction

d.        total internal reflection

4.       The principle which allows a rainbow to form is

a.        refraction

b.        polarization

c.        dispersion

d.        total internal reflection

5.       Light has a wavelength of 600 nm in a vacuum.  It passes into glass, which has an index of
refraction of 1.50.  What is the wavelength of the light in the glass?

          a.        600 nm

          b.        500 nm

          c.        400 nm

          d.        300 nm

6.       Light has wavelength 600 nm in a vacuum.  It passes into glass, which has an index of
refraction of 1.50.  What is the frequency of the light inside the glass?

a.        3.3X10¹⁴ Hz

b.        5.0X10¹⁴ Hz

          c.        3.3X10⁵ Hz

          d.        5.0X10⁵ Hz

7.       Light has a wavelength of 600 nm in a vacuum.  It passes into glass, which has an index of
refraction of 1.50.  What is the speed of the light in the glass?

          a.        3.0X10⁸ m/s

b.        2.5X10⁸ m/s

          c.        2.0X10⁸ m/s

          d.        1.5X10⁸ m/s

8.       When a light wave enters into a medium of different optical density,

a.   its speed and frequency change.

b.   its speed and wavelength change.

c.   its frequency and wavelength change.

d.   its speed, frequency, and wavelength change.

9.       Light of wavelength 575 nm falls on a double-slit and the third order bright fringe is seen
at an angle of 6.5 degree.  What is the separation between the double slits?

a.   5.0 micro-m

b.   10 micro-m

c.   15 micro-m

d.   20 micro-m

10.     One beam of coherent light travels path P₁ in arriving at point Q and another coherent beam
travels path P₂ in arriving at the same point.  If these two beams are to interfere destructively,
the path difference P₁ - P₂ must be equal to

a.   an odd number of half-wavelengths.

b.   zero.

c.   a whole number of wavelengths.

d.   a whole number of half-wavelengths.

11.     Two beams of coherent light travel different paths arriving at point P.  If the maximum
constructive interference is to occur at point P, the two beams must

a.   arrive 180ø out of phase.

b.   arrive 90ø out of phase.

c.   travel paths that differ by a whole number of wavelengths.

d.   travel paths that differ by an odd number of half-wavelengths.

12.     Two light sources are said to be coherent if they

a.   are of the same frequency.

b.   are of the same frequency, and maintain a constant phase difference.

c.   are of the same amplitude, and maintain a constant phase difference.

d.   are of the same frequency and amplitude.

13.     Light of wavelength 580 nm is incident on a slit of width 0.300 mm.  An observing screen is
placed 2.00m from the slit.  Find the position of the first order dark fringe from the center of
the screen.

a.   0.26 mm

b.   1.9 mm

c.   3.9 mm

d.   7.7 mm

14.     A diffraction grating has 4000 lines per cm.  The angle between the central maximum and
the third order maximum is 36ø.  What is the wavelength of the light?

          a.   240 nm

          b.   490 nm

          c.   570 nm

          d.   620 nm

15.    On a clear day, the sky appears to be more blue toward the zenith (overhead) than it does
toward the horizon.  This occurs because

a.   the atmosphere is denser higher up than it is at the earth's surface.

b.   the temperature of the upper atmosphere is higher than it is at the earth's surface.

c.   the sunlight travels over a longer path at the horizon, resulting in more absorption.

d.   none of the above is true.

Answers:

1.    c
2.    d
3.    b
4.    c
5.    c
6.    b
7.    c
8.    b
9.    c
10.    a
11.    c
12.    b
13.    c
14.    b
15.    c