Physical Science Exam 2

The properties of several different materials are being compared. If the samples all have the same volume, the one with the greatest mass also has the greatest?

Density

Which of the following quantities is independent of the size and shape of an object composed of a given material?

Density

When heat is added to a body of matter, the resulting temperature increase does not depend upon?

Its shape

Superconductivity occurs in certain substances

Only at very low temperatures

Which of the following statements is not true?

Protons and electrons have equal masses

Which of the substances below have the highest specific heat?

Water

A magnet does not exert a force on

a stationary electric charge

The wavelength of a sound wave is not related to its

amplitude

The pressure at the bottom of a barrel filled with liquid does not depend on the?

area of the liquid surface

The "heat death" of the universe refers to a possible future in which all of its molecules are

at rest?

When a magnetized iron bar is strongly heated, its magnetic field

becomes weaker

Light of which of the following colors has the longest wavelength?

blue

A drawing of the field lines of a magnetic field provides information on

both the direction and the strength of the field

Heat transfer in a vacuum

can take place only by radiation.

The maximum possible efficiency of a heat engine

depends on the ratio between the exhaust and intake temperatures

The entropy of a system is a measure of its

disorder

A current is flowing south along a power line. Neglecting the earth's field, the direction of the magnetic field under the power line is

east

Atoms and molecules are normally

electrically neutral

A kilowatt-hour is a unit of

energy

When waves go from one place to another, they carry

energy

When a sound wave goes from air into water, the quantity that remains unchanged is its

frequency

Suppose there were molecules that had no attraction whatsoever for one another. A collection of such molecules would form a?

gas

When a liquid freezes to become a solid,

it gives off heat

When a liquid becomes a vapor,

it must absorb heat

Ice floats on water because?

its density is less than that of water

first law of thermodynamics is the same as the

law of conservation of energy

You are looking at the bottom of a lake 1.2 m deep from a boat. To you the lake seems to be

less than 1.2 m deep

Heat transfer by conduction occurs

liquids, solids, and gases

In order for an object to sink when placed in water, the object's average density must be?

more than that of water

Which of the following statements is correct?

moving electrons constitute electric currents

The current with which a transformer is used

must be ac

Heat transfer by convection occurs

only in liquids and gases

In a transverse wave, the individual particles of the medium move

perpendicular to the direction of travel.

Which of the following effects does not occur in all types of wave

polarization

A molecule that has lost an electron becomes a

positive ion

Sound waves travel fastest through

solids

A magnet attracts

some substances and repels others

A sample of a gas is expanded to twice its original volume while its temperature is held constant. Relative to their original average energy, the new average energy of the molecules is?

the same

The higher the frequency of a wave,

the shorter its wavelength

An absolute temperature of 100 K is the same as a Celsius temperature of

-173°C

At which of the following Celsius temperatures will a Fahrenheit thermometer show the same reading in degrees

-40°C

Molecular motion in a gas is the minimum possible at?

0 K

The specific heat of water is 4.2kJ/kg°C. The heat needed to warm 8kg of water from 20°C to 70°C is

1680 kJ

The current in a 24-W, 12-V light bulb is

2 A

The density of brass is 8 × 103 kg/m3. The volume occupied by 320 g of brass is

38cm^3

The primary coil of a transformer has 200 turns and its secondary coil has 40 turns. If the current in the secondary coil is 25 A, the current of the primary coil is?

5 A

A temperature of 20°C is the same as

68°F

The primary coil of a transformer is connected to a source of alternating current of voltage V. The voltage of the secondary current is?

Any of these choices could be correct, depending on the ratio of turns in the transformer coils.