Question 1

Which of the following best describes how electromagnetic waves are generated?

Accepted Answer

By the oscillation of electric and magnetic fields due to accelerated charges.

Question 2

If an electron vibrates up and down 1000 times each second, what is the frequency $$f of $$the electromagnetic wave it generates?

Accepted Answer

$$f = 1000\ \mathrm{Hz}$$

Question 3

Which region of the electromagnetic spectrum has the shortest wavelength?

Accepted Answer

Gamma rays

Question 4

Which of the following is fundamentally different from the others?

Accepted Answer

Sound waves

Question 5

What happens to the speed of light as it passes from air into glass?

Accepted Answer

It decreases to about $$0.67c$$

Question 6

Why is glass transparent to visible light but not to ultraviolet or infrared light?

Accepted Answer

Visible light causes only electrons to vibrate, while infrared and ultraviolet cause entire atoms or molecules to vibrate, leading to absorption.

Question 7

Strictly speaking, the photons of light incident on glass are:

Accepted Answer

Absorbed and re-emitted by electrons in the glass, so the exiting photons are not the same as the incident ones.

Question 8

Compared with the frequency of illuminating light on a sheet of transparent plastic, the frequency of light that is transmitted:

Accepted Answer

Is the same.

Question 9

Which part of the eye is responsible for most of the bending (refraction) of light entering the eye?

Accepted Answer

Cornea

Question 10

What is the function of rods in the retina?

Accepted Answer

They handle vision in low light conditions.

Question 11

A solar eclipse occurs when:

Accepted Answer

The Moon passes between the Sun and Earth, casting a shadow on Earth.

Question 12

Which of the following best explains why wet surfaces appear darker than dry surfaces?

Accepted Answer

Light bounces inside the transparent wet region, absorbing energy with each bounce before reaching your eye.

Question 13

What is the term for the region of total shadow in an eclipse?

Accepted Answer

Umbra

Question 14

Which of the following materials has the lowest average speed of light?

Accepted Answer

Diamond

Question 15

Which part of the retina is responsible for the most distinct vision?

Accepted Answer

Fovea

Question 16

A beam of light passes from air (speed $$c) $$into water (speed $$0.75c). If $$the wavelength in air is $$\$$lambda_0$$, what is the wavelength in water?

Accepted Answer

$$\lambda = 0.75\$$lambda_0$$

Question 17

Which of the following best describes why metals are shiny?

Accepted Answer

Free electrons in the metal vibrate and emit their own light as reflection.

Question 18

Which of the following is NOT a property of electromagnetic waves?

Accepted Answer

They require a medium to propagate.

Question 19

Which of the following statements about the penumbra is correct?

Accepted Answer

It is a region where some, but not all, of the light is blocked.

Question 20

Which of the following best explains why we are more sensitive to motion in our peripheral vision?

Accepted Answer

Rods, which are more sensitive to motion and low light, predominate toward the periphery of the retina.

Chapter 26: Properties of Light – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards