Science Test 2

c

The temperature of boiling water is _______

A) 100°C. B) 212°F. C) both of these

b

Which temperature scale has the smallest sized degrees? _______
A) Kelvin B) Fahrenheit
C) Celsius D) none of the above

c

At absolute zero, a substance has _______
A) absolutely no molecular motion. B) no volume.
C) no more energy to give up. D) all of the above

d

Heat is _______
A) radiant energy. B) temperature.
C) thermal energy. D) thermal energy flowing from hot to cold

c

Heat energy is measured in units of _______
A) joules. B) calories.
C) both joules and calories. D) degrees.

a

When you touch a hot penny in the sunlight with your finger, energy flows _______
A) from the penny to your finger.
B) from your finger to the penny.
C) both ways.

c

Heat is thermal energy that flows from _______
A) high thermal pressure to low thermal pressure.
B) high energy to low energy.
C) hot to cold.
D) all of the above

c

If a room is cold it is usually due to the _______
A) presence of the entity known as cold.
B) low air pressure.
C) lack of adequate thermal energy

b

San Francisco Chef Manual rates the energy content of foods in units of _______
A) calories. B) Calories.
C) Celsius degrees. D) joules.

a

Which law of thermodynamics is a restatement of the conservation of energy as it applies to thermal systems? ______
A) First law B) Second law C) Third law D) all of the above

b

Which law of thermodynamics addresses the direction of heat flow? ______
A) First law B) Second law C) Third law D) all of the above

c

Which law of thermodynamics states that no system can reach absolute zero? ______
A) First law B) Second law C) Third law D) all of the above

b

When work is done by a system and no heat is added, the temperature of the system ______
A) increases. B) decreases. C) remains unchanged

b

Leaving a hot oven door open in a closed room on a cool day ______
A) decreases room temperature.
B) increases room temperature.
C) doesn't affect room temperature.

Because a refrigerator operates by a motor, leaving the refrigerator door open for hours in a closed room ______
A) decreases room temperature.
B) increases room temperature.
C) doesn't affect room temperature

c

The direction of natural processes is from states of ______
A) lower order to higher order. B) imbalance to equilibrium.
C) higher order to lower order. D) disorganization to organization.

a

As a system becomes more disordered, entropy ______
A) increases. B) decreases. C) remains the same.

c

A substance that heats up relatively quickly has a ______
A) high specific heat capacity.
B) high or low specific heat capacity.
C) low specific heat capacity.

c

San Francisco has milder winters than Washington D.C. due to water's high ______
A) conductivity.
B) temperature in the Pacific Ocean.
C) specific heat capacity.

a

The specific heat capacity of aluminum is more than twice that of copper. Place equal masses of aluminum and copper wire in a flame and the wire to heat up quickest will be ______
A) copper. B) aluminum. C) both the same

b

The operation of a bimetallic strip relies on differences in ______
A) heat capacities of metals.
B) expansions of metals.
C) conductivities of metals.

b

If water at 0°C slightly increases in temperature, the water ______
A) expands. B) contracts. C) neither of these

b

Before ice can form on a lake, all the water in the lake must be cooled to ______
A) a value slightly below 0°C.
B) 4°C.
C) 0°C.

c

The temperature at the bottom of Lake Tahoe, high in the Sierra Mountains in California, at this moment is ______
A) above 4°C. B) below 4°C. C) 4°C. D) uncertain.

b

Conduction has most to do with electrons and atoms ______
A) changing identities. B) bumping into one another.
C) flowing past one another. D) radiating energy.

a

A good heat conductor is a ______
A) poor insulator. B) good insulator. C) neither of these

b

A poor conductor of heat is a ______
A) poor insulator. B) good insulator. C) neither

a

When you touch a nail stuck in ice, energy flows from ______
A) your hand to the ice. B) the ice to your hand.
C) both of these D) none of the above

c

Your bare feet feel warmer on a rug than on a tile floor because the rug ______
A) has more thermal energy than tile. B) is usually warmer than tile.
C) is a better insulator than tile. D) all of the above

c

The main reason you can walk barefoot on red-hot coals of wood without burning your feet involves ______
A) low temperature of the coals.
B) mind over matter techniques.
C) low conductivity of the coals.

b

A bare roof of a warmly heated home on a snowy day indicates ______
A) good insulation. B) an unwanted flow of heat.
C) a change of phase. D) all of the above

b

The higher the temperature of an object, the  ______
A) longer the wavelengths it radiates.
B) shorter the wavelengths it radiates.
C) none of the above

c

The process of convection occurs in  ______
A) solids. B) liquids. C) fluids. D) gases.

a

Convection currents in the air near a seashore are produced by ______
A) unequal heating of land and water. B) varying temperatures.
C) shifting winds. D) none of the above

a

If a volume of air is warmed, it expands. If a volume of air expands, it ______
A) cools. B) warms. C) neither of these

b

When air is compressed, its temperature ______
A) decreases. B) increases. C) neither of these

b

In a muggy region, the extra warmth you often feel is mainly due to ______
A) evaporation. B) condensation.
C) sublimation. D) none of the above

a

A substance most commonly emits heat energy by the process of ______
A) radiation. B) conduction.
C) convection. D) none of the above

b

The higher the frequency of a wave, the ______
A) longer the wavelength. B) shorter the wavelength. C) neither of these

a

Hot water will cool to room temperature faster in a  ______
A) black pot.
B) silver pot.
C) depends on size, not color

a

To minimize heat loss it is best that a teapot be ______
A) silver.
B) black.
C) depends on size, not color

c

A good absorber of radiation is a  ______
A) good reflector. B) poor emitter of radiation.
C) good emitter of radiation. D) none of the above

b

If air were a better conductor than it is, nighttimes on Earth would be ______
A) considerably warmer.
B) considerably colder.
C) not appreciably different in temperature.

a

A red-hot piece of iron will cool slower in a ______
A) warm room. B) cold room. C) same in each

b

If the greenhouse effect on Earth were absent, Earth's average temperature would be about ______

A) appreciably warmer. B) -18°C. C) as it is now.

b

Glass is largely opaque to  ______
A) visible light. B) infrared light. C) ultraviolet light.

a

Long ago a runaway greenhouse effect greatly transformed the planet ______
A) Venus. B) Mercury.
C) Mars. D) none of the above

a

Glass in a florist's greenhouse blocks radiation of relatively  ______
A) low frequencies. B) all frequencies. C) high frequencies

b

Evaporation is a cooling process because ______
A) heat is radiated during the process.
B) the more energetic molecules escape the liquid.
C) of conduction and convection.
D) none of the above

a

After taking a shower and stepping outside the shower stall, the chill you often feel is mainly due to ______
A) evaporation. B) condensation.
C) sublimation. D) none of the above

c

Sublimation is a change of phase from solid to gas without ______
A) a change of temperature.
B) a transfer of energy.
C) passing through the liquid phase.

b

The process of boiling water tends to ______
A) warm the water. B) cool the water.
C) both of these D) none of the above

b

Food is cooked faster in a pressure cooker due to its ______
A) greater rate of bubble formation in the water.
B) higher temperature.
C) higher thermal energy.
D) none of the above

c

A good cook knows that the temperature of violently boiling water is ______
A) actually lower than 100°C. B) higher than that of simmering water.
C) the same as that of simmering water. D) neither of the above

b

As water changes to ice, water molecules ______
A) absorb energy. B) release energy.
C) lose the quality of wetness. D) retain their energy

a

The temperature at which water freezes is the same as the temperature at which ______
A) ice melts. B) water boils. C) both of these D) neither of these

b

The addition of salt to water affects its ______
A) liquidity. B) freezing point.
C) crystal composition. D) viscosity.

a

When a gas is changed to a liquid phase, the gas ______
A) releases energy. B) absorbs energy. C) neither of these

a

When a solid is changed to a liquid phase, the solid ______
A) absorbs energy. B) releases energy.
C) neither of these D) none of the above

b

We feel uncomfortably warm on a muggy day because water molecules are ______
A) preventing the evaporation from our moist bodies.

B) condensing on our bodies.
C) evaporating from our moist bodies

a

When snow falls, the surrounding air is normally  ______
A) warmed. B) cooled.
C) both of these D) none of the above

c

Steam burns are much more damaging than boiling-water burns because steam ______
A) is hotter. B) is gaseous.
C) releases more thermal energy. D) has a higher temperature.

c

If you keep decreasing the kinetic energy of atoms in a liquid, the liquid may ______
A) condense. B) melt. C) solidify.

b

If you keep increasing the kinetic energy of atoms in a solid ______
A) freezing may occur. B) melting may occur. C) evaporation may occur.

a

Which of these scientists pioneered the study of electricity?  ______
A) Benjamin Franklin B) Galileo
C) Isaac Newton D) all of the above

b

The nucleus of an atom is charged ______
A) negatively. B) positively.
C) both of these D) none of the above

b

Compared to the mass of a proton, the mass of an electron is ______
A) identical. B) very much less. C) greater

c

The fundamental force underlying all chemical reactions is ______
A) centripetal. B) nuclear. C) electrical. D) gravitational.

b

An electron and a proton ______
A) repel each other.
B) attract each other.
C) attract or repel depending on distance.

c

A positive ion has a deficiency of ______
A) negative ions. B) neutrons. C) electrons

a

As you comb your hair, electrons are rubbed onto the comb, which becomes ______
A) negatively charged. B) ionized. C) positively charged.

a

If you strip electrons from an atom, the atom becomes a ______
A) positive ion. B) different element. C) negative ion

c

Charge carriers in a metal are electrons rather than protons because electrons are ______
A) smaller. B) negative. C) loosely bound. D) all of the above

d

A main difference between gravitational and electric forces is that electric forces ______
A) obey the inverse-square law. B) attract.
C) are weaker. D) repel or attract.

a

When the distance between two charges is halved, the electric force between the charges  ______
A) quadruples. B) doubles.
C) is reduced by one-quarter. D) is half.

d

Two charged particles 1 m apart exert a 1-N force on each other. If the magnitude of each charge is doubled, the force on each particle will be ______
A) 1 N. B) 2 N. C) 8 N. D) 4 N

a

Electric field lines about a point charge extend ______
A) outward when the charge is positive.

B) in circles.
C) outward when the charge is negative

c

Food cooked in a microwave oven depends on electrical ______
A) resistance changes. B) field strength.
C) charge polarization. D) conduction

d

Electric potential is measured in units of ______
A) watts. B) joules. C) amperes. D) volts.

a

Electric potential is the ratio of electric energy to the amount of electric ______
A) charge. B) current. C) voltage. D) resistance.

c

When a battery does 24 J of work on 10 C of charge, the voltage it supplies is ______
A) 24 V. B) 240 V. C) 2.4 V. D) 4.2 V.

a

A charged balloon illustrates that something can have a great amount of ______
A) voltage and a small potential energy. B) potential energy and a low voltage.
C) both voltage and potential energy. D) none of the above

b

Voltage is most similar to ______
A) current. B) pressure. C) resistance. D) all of the above

a

A term for electric pressure is ______
A) voltage. B) electric resistance. C) current.

a

The amount of energy given to each coulomb of charge flowing through a 12-V battery is ______
A) 12 J. B) 12 V. C) 12 A. D) all of the above

a

An ampere is a unit of electric ______
A) current. B) resistance. C) pressure. D) all of the above

d

A coulomb of charge flowing in a bulb filament powered by a 6-volt battery is provided with ______
A) 6 ohms. B) 6 amperes. C) 6 watts. D) 6 joules.

b

To say a circuit is dc is to say that current in the circuit  ______
A) is parallel to the connecting wires.
B) has a single direction.
C) alternates only slowly.

b

Direct current is normally produced by a ______
A) generator. B) battery. C) both of these D) neither of these

b

Alternating current is normally produced by a ______
A) battery. B) generator. C) both of these D) neither of these

b

Current that is typically 60 hertz is ______
A) direct current. B) alternating current.
C) either of these D) neither of these

c

The number of electrons delivered daily by power utilities to an average American home during a typical week is ______
A) 110. B) 220.
C) zero. D) billions of billions.

d

The unit of resistance is named after ______
A) Charles Coulomb. B) Micheal Faraday.
C) Benjamin Franklin. D) Georg Simon Ohm.

b

Which of these, all of the same length, has the greater electrical resistance? ______
A) an iron rod B) a rubber rod
C) a copper rod D) all about the same

b

Which of these, both of the same length, has the greater electrical resistance? ______
A) a thick copper wire B) a thin copper wire
C) both about the same D) need more information

a

The electric resistance of a superconductor is ______
A) zero. B) usually lower than ordinary resistors.
C) infinite. D) none of the above

c

Ohm's law tells us that the amount of current produced in a circuit is ______
A) inversely proportional to resistance. B) directly proportional to voltage.
C) both of these D) neither of these

a

When the voltage across a steady resistance is doubled, the current ______
A) is doubled. B) remains the same.
C) is half. D) is quadrupled.

b

Electrical resistance is greater for ______
A) wet skin. B) dry skin. C) both the same

c

The current through a 10-ohm resistor connected to a 120-V power supply is _____
A) 120 A. B) 10 A. C) 1 A. D) 12 A.