chapter 12 sample

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chapter 12 sample

Multiple Choice
Identify the choice that best completes the statement or answers the question.

Sound travels fastest in

a.	air at 0º C.	c.	rubber.
b.	air at 25º C.	d.	sea water.

The pitch of a sound is most closely related to the

a.	frequency of vibrations.
b.	distance from the sound source.
c.	medium through which the sound travels.
d.	intensity of the sound.

The unique sound quality of a clarinet or a violin is caused by the

a.	forced vibrations that occur at natural frequencies.
b.	length of standing waves in the fundamental frequency.
c.	relative intensity of different harmonics in each note.
d.	relative number of harmonics.

The structure within the cochlea containing hair cells that vibrate at different natural frequencies is the

a.	eardrum.	c.	inner ear.
b.	basilar membrane.	d.	hammer and anvil.

A sonar system measures distance by determining the

a.	density of a body of water.
b.	time it takes for sound to be absorbed.
c.	difference between regular sound waves and ultrasound.
d.	time it takes for sound waves to bounce off a surface.

Which property of light is not explained by the wave model of light?

a.	Light produces interference patterns.
b.	Light is diffracted when it passes through a narrow opening.
c.	Blue light can knock electrons off a plate but red light cannot.
d.	Light reflects when it meets a mirror, but it refracts when it passes through a lens.

The amount of energy in a photon of light is proportional to the

a.	medium through which it travels.
b.	shape of the light wave it creates.
c.	speed of the corresponding light wave.
d.	frequency of the corresponding light wave.

The rate at which light energy flows through a given area of space is referred to as its

a.	speed.	c.	intensity.
b.	wavelength.	d.	energy.

Which type of waves has wavelengths longer than microwaves?

a.	infrared	c.	radio waves
b.	visible light	d.	gamma rays

10.

Which type of electromagnetic radiation is used to kill cancer cells?

a.	microwaves	c.	ultraviolet rays
b.	gamma rays	d.	sunlight

11.

Short-range radar works by sending a signal out from a control tower that is

a.	analyzed by a Doppler scanner on the ground.
b.	reflected off a plane back to the control tower.
c.	increased in intensity as it passes through the atmosphere.
d.	scanned and analyzed by a receiver on board an airplane.

12.

When light rays reflect off a rough surface, they

a.	scatter in many different directions.
b.	converge toward the normal.
c.	diverge away from the normal.
d.	decrease their speed and change their angle.

13.

The law of reflection states that when light rays reflect off a surface the angle of incidence

a.	is one-half the angle of reflection.	c.	is twice the angle of reflection.
b.	equals the angle of reflection.	d.	equals the angle of refraction.

14.

Which statement about mirrors is incorrect?

a.	Flat mirrors create virtual images.
b.	Concave mirrors can create real or virtual images.
c.	Curved mirrors distort images by reflecting light according to the law of reflection.
d.	Only convex mirrors work according to the law of reflection.

15.

You look at a red tulip, with green leaves, under green light. What would you see?

a.	a green flower with green leaves	c.	a yellow flower with black leaves
b.	a black flower with green leaves	d.	a black flower with black leaves

16.

When light moves from a material in which its speed is higher to a material in which its speed is lower, it is

a.	bent toward the normal.	c.	reflected off the boundary.
b.	bent away from the normal.	d.	changed into a virtual image.

17.

A virtual image caused by reflection of light in the atmosphere is called

a.	a prism.	c.	a mirror.
b.	a lens.	d.	a mirage.

18.

Light that enters one end of a fiber optic cable reaches the other end by means of

a.	dispersion.	c.	repeated intensification.
b.	magnification.	d.	total internal reflection.

19.

Which statement about a diverging lens is correct?

a.	It bends light inward and can create either a virtual or a real image.
b.	It bends light inward and can only create a real image.
c.	It bends light outward and can create either a virtual or a real image.
d.	It bends light outward and can only create a virtual image.

20.

Light rays that pass through a lens change direction because

a.	each light ray strikes the curved surface at a different angle.
b.	they are refracted.
c.	light is broken up into many different colors.
d.	virtual images always appear slightly larger than real images.

21.

Which statement about the lens of the eye is incorrect?

a.	It is made of glassy fibers.	c.	It has a fixed curvature.
b.	It is behind the iris.	d.	It focuses light rays on the retina.

22.

Which structure within the eye is responsible for the largest percentage of refraction of light?

a.	retina	c.	lens
b.	cornea	d.	iris

23.

The effect in which white light separates into different colors is called

a.	magnification.	c.	reflection.
b.	refraction.	d.	dispersion.

24.

White light breaks up into different colors when it passes through a prism because of

a.	differences in wave speed.
b.	total internal dispersion.
c.	a combination of refraction and reflection.
d.	droplets in the air.

25.

Which drawing illustrates the law of reflection?

a.	a	c.	c
b.	b	d.	d

Completion
Complete each statement.

26.

A high-pitched sound results when a string or a column of air ____________________.

27.

The note A-natural sounds different on a tuning fork, a violin, and a flute because of the relative amplitudes of ____________________.

28.

Resonance occurs when the vibration of one object causes another object to vibrate at a(n) ____________________.

29.

The three small bones in your middle ear are the ____________________, the ____________________, and the ____________________.

30.

In your inner ear, different parts of the ____________________ vibrate at different natural frequencies.

31.

Sound waves with frequencies higher than 20 000 Hz are referred to as ____________________ waves.

32.

Sonograms are possible because some ultrasound waves are ____________________ when they pass from one type of material to another.

33.

The two most common models of light describe it as a wave or as a stream of ____________________.

34.

In the particle model of light, individual "packets" of light are called ____________________.

35.

The energy of light is proportional to the ____________________ of the corresponding ____________________.

36.

In a vacuum, all light travels at the same speed, which is ____________________.

37.

All possible kinds of light, at all energies, frequencies, and wavelengths, make up the ____________________.

38.

The electromagnetic waves with the highest energy and shortest wavelengths are classified as ____________________.

39.

____________________ are used for cooking as well as for communication.

40.

Reflection of light into random directions is called ____________________ reflection.

41.

The theoretical line perpendicular to the surface where light hits a mirror is called the ____________________.

42.

The law of reflection states that the angle of ____________________ is the same as the angle of ____________________.

43.

In a(n) ____________________ image, light rays really exist at the point where the image appears.

44.

Colors that combine to produce white are called ____________________ colors.

45.

An object looks red if it ____________________ red light and ____________________ all other colors.

46.

White light actually contains all the visible wavelengths of the ____________________.

47.

If a light moves from a material in which its speed is lower to one in which its speed is higher, the ray is bent away from the ____________________.

48.

A lens that bends light inward is called a(n) ____________________ lens.

49.

Light first enters the eye through a transparent tissue called the ____________________.

50.

The cone cells in the eye allow ____________________ vision, and the rod cells are more sensitive to ____________________ light.