Chapter 13

Question 1

The direction of electromagnetic wave propagation is

Answer 1

perpendicular to the electric field

perpendicular to the magnetic field

Question 2

Electromagnetic radiation that has a wavelength of 900 nm is best classified as

Answer 2

infrared.

Question 3

Many properties of light have been discovered. The most important of these properties to explain the production of shadows is that light

Answer 3

travels in a straight line.

Question 4

Electromagnetic radiation with a frequency of 6.10*10^21 Hz is best classified as

Answer 4

gamma.

Question 5

Electromagnetic radiation that has a wavelength of 260 m is classified as

Answer 5

radio.

Question 6

Maxwell was a mathematician who predicted that light and electromagnetic radiation are one and the same thing. The most important evidence that Maxwell provided was that

Answer 6

light and electromagnetic radiation both travelled at similar speeds.

Question 7

EMR is the result of accelerating charges. Visible light is produced by

Answer 7

electron transitions from higher to lower energy levels in atoms.

Question 8

Roemer gathered data to measure the speed of light by observing

Answer 8

light reflected from Jupiter’s moon Io to Earth.

Question 9

An electromagnetic wave is travelling horizontally and to the east. At any given instant, the electric field of the electromagnetic wave points horizontally northward. At this same instant, the magnetic field could point

Answer 9

vertically upward.

Question 10

Which of the following statements about electromagnetic radiation in a vacuum is false?

Answer 10

Different types of electromagnetic radiation have different wavelengths and speeds.

Question 11

In general, Huygens’ principle states that

Answer 11

many point sources on a wave result in a wave front.

Question 12

True

Answer 12

Light is a transverse wave.
Light, when polarized, vibrates in one plane.
Light, when unpolarized, vibrates in many planes.

Question 13

Images that are formed by a plane mirror

Answer 13

are virtual, erect, and unmagnified.

Question 14

Frequency is more reliable than wavelength for classifying colours of light because wavelength changes during

Answer 14

refraction.

Question 15

When performing an experiment similar to Young’s double-slit experiment, a student observes that the distance between antinodes triples. The most likely change that the student made in order to observe this effect is that he

Answer 15

decreased the distance between the slits to one-third the original.

Question 16

Polarization of light can best be explained by considering light to behave as a

Answer 16

transverse wave.

Question 17

Poisson’s bright spot is the result of

Answer 17

diffraction and interference.

Question 18

For a light interference pattern formed when monochromatic light passes through two narrow slits, the second-order nodal line is found

Answer 18

one and a half wavelengths farther from one source than the other.

Question 19

The first calculation that gave an estimate of the speed of light was not accepted until after the death of the scientists involved. They used measurements of the

Answer 19

time required for light to travel across Earth’s orbit.

Question 20

The speed of an electromagnetic wave is determined by the

Answer 20

medium.

Question 21

Roemer and Huygens first determined a value for the speed of light that was close to its theoretical value. They

Answer 21

measured the time it took for light to cross the diameter of Earth’s orbit while observing the eclipse of Jupiter’s moons.

Question 22

Diffuse reflection results from

Answer 22

incoming parallel rays, reflecting according to the law of reflection but not parallel, to produce a blurry image from a less-than-smooth reflective surface.

Question 23

Optical fibres depend on properties

Answer 23

Light travels in straight lines.
Light reflects according to the law of reflection.
Light in an optically dense material may reflect internally.

Question 24

Effects of light diffraction were not originally observed in normal situations because visible light

Answer 24

has short wavelengths.

Question 25

Specular reflection results from

Answer 25

incoming parallel rays reflecting according to the law of reflection and parallel to produce a clear image from a perfectly smooth reflective surface.

Question 26

A student uses an optical bench to investigate images formed by concave mirrors. When the object is placed at a distance that is twice the focal length of the mirror, the student observes

Answer 26

an inverted and same size image.

Question 27

If the angle of deviation from the central maximum to the first antinodal line increased from its original position, it is most likely because the

Answer 27

slits were moved closed together.

Question 28

A prism is made of a material with an index of refraction of 1.55 for all types of electromagnetic radiation. The statement that is incorrect regarding this prism is:

Answer 28

white light entering the prism will leave as white light.