Physical Science
The entropy of a system is a measure of its
Disorder.
Suppose there were molecules that had no attraction whatsoever for one another. A collection of such molecules would form a
gas.
Ice floats in water because
its density is less than that of water.
Of the substances below, the one with the highest specific heat is
Water.
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 wavelength of a sound wave is not related to its
Amplitude.
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.
The pressure at the bottom of a barrel filled with liquid does not depend on the
Area of the liquid surface.
When a magnetized iron bar is strongly heated, its magnetic field
Becomes weaker.
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.
When a sound wave goes from air into water, the quantity that remains unchanged is its
Frequency.
Heat transfer by conduction occurs
In liquids, solids and gases.
When a liquid freezes to become a solid
It gives off heat.
When a liquid becomes a vapor
It must absorb heat.
When heat is added to a body of matter, the resulting temperature increase does not depend upon
Its shape.
The 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.
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 "heat death" of the universe refers to a possible (although improbable) future in which all of its molecules are
Moving with the same average speed.
The current with which a transformer is used
Must be ac.
Superconductivity occurs in certain substances
Only at very low temperatures.
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 one of the following effects does not occur in all types of wave?
Polarization.
A molecule that has lost an electron becomes a
Positive ion.
A kilowatt hour is a unit of
Power.
Which of the following statements is not true?
Protons and electrons have equal masses.
Light of which of the following colors has the longest wavelength?
Red.
Sound waves travel fastest in
Solids.
A magnet attracts
Some substances and repels others.
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 4.2 kJ/kg°C. The heat needed to warm 8 kg 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
38 cm3
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 in the primary coil is
5 A.
A temperature of 20°C is the same as
68°F
A magnet does not exert a force on
A stationary electric charge.
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.
The maximum possible efficiency of a heat engine
Depends on the intake temperature.
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.
When waves go from one place to another, they carry
Energy.
