Physics Test 9

An ampere is a unit of electric a. voltage b. current c. resistance

B

Charge carries in a metal are electrons rather than protons because electrons are a. smaller b. loosely bound c. negative d. none of the above

B

Conducting materials are composed of atoms with a. vastly more charge than insulators b. loose outer electrons c. strong cohesive forces between them d. excess neutrons compared with protons

B

Electrons flow in a wire when there is a. a difference in potential energy across its ends b. a potential difference across its ends c. an imbalance of charges in the wire d. none of the above

B

If two copper wires of the same length have different thickness, then the thicker wire has a. more resistance b. less resistance c. both the same

B

A 60-W and a 100-W light bulb are connected in parallel to a 120-V outlet. Which bulb draws more current? a. 100-W bulb b. 60-W bulb c. both the same

A

An electron and a proton a. attract each other b neither attract nor repel each other c. repel each other

A

As more lamps are connected in a series circuit, the overall current in the power source a. decreases b. stays the same c. increases

A

Assume that 10 J of work pushes a charge initially at rest into an electric field. If the charge is then released, it flies back to its starting position with a kinetic energy of a. 10 J b. zero c. 5 J d. more than 10 J e. need more information

A

If 10 J of work is used in pushing 1 C of charge into an electric field, its electric potential relative to its starting position is a. 10 V b. more than 10 V c. less than 10 V d. none of the above

A

Insulating materials are composed of atoms with a. tightly bound outer electrons b. weak cohesive forces c. excess protons d. vastly more charge than conductors

A

Just as a sustained flow of water in a hydraulic circuit needs a pump, in electric circuits the flow of charge needs a. voltage b. current c. resistance

A

The amount of current in an incandescent bulb rated 75W 120V is about a. 0.6 A b. more than 1.2 A c. 0.4 A d. 1.2 A

A

The fundamental force underlying all chemical reactions is a. electrical b. centripetal c. gravitational d. nuclear e. none of the above

A

The unit of electrical resistance is the a ohm b volt c. ampere d. none of the above

A

To become a positive ion, an atom must a. lose an electron b. gain an electron c. gain a proton d. lose a proton

A

Two charged particles repel each other with a force F. If the charge of one of the particles is doubled and the distance between them is also doubled, then the force will be a. F/2 b. F c. 2 F d. F/4 e. none o the above

A

Just as water flows from a region of high pressure to a region of low pressure, electric charge flows from a region of a. high potential energy to a region of low potential energy b. high electric pressure to a region of low electric pressure c. deep to shallow regions d. all of the above

B

On some early automobiles both headlights failed when one bulb burned out. The headlights were likely connected in a. parallel b. series c. haste d. perpendicular

B

When the distance between two charges is halved, the electrical force between them a. doubles b. quadruples c. is reduced by 1/4 d. halves e. none of the above

B

A 4-ohm and 6-ohm resistor connected in parallel have an equivalent resistance of a. 4 ohms b. 5.5 ohms c. 2.4 ohms d. 5 ohms e. 10 ohms

C

A 60-W and a 100-W light bulb are connected in series to a 120-V outlet. Which bulb draws more current? a. 60-W bulb b. 100-W bulb c. both of the same

C

A fundamental rule of electricity is that a. unlike kinds of charges attract b. like kinds of charges repel c. both A and B d. none of these

C

A suitable electric pump in an electric circuit is a a. chemical battery b. generator c. both A and B d. none of these

C

Although the energy per coulomb of a high-voltage party balloon is high, the energy transfer that occurs if you touch it is low due to a. the small electric potential b. rubber being a poor conductor c. the relatively small amount of charge d. all of the above

C

An electron is pushed into an electric field where it acquires a 1-V potential. If two electrons are pushed the same distance into the same field, the electrical potential of the two electrons is a. 0.25 V b. 0.5 V c. 1 V d. 4 V e. 2 V

C

As more lamps are connected in a parallel circuit, the overall current in the power source a. decreases b. stays the same c. increases

C

Heat a copper wire and its electric resistance a. remains unchanged b. decreases c. increases

C

If you comb your hair and the comb becomes positively charged, then your hair becomes a. positively charged b. uncharged c. negatively charged

C

In a circuit powered by a battery, charge a. flows through the battery b. is energized by the battery c. both of these c. neither of these

C

Modern automobile headlights are connected in a. series b. a perpendicular orientation c. parallel d. none of the above

C

Ohm's law tells us that the amount of current produced in a circuit is a. directly proportional to voltage b. inversely proportional to resistance c. both of these d. neither of these

C

The current drawn by a 1200-W toaster connected to a 120 V is 10 A. The resistance of the toaster coils is a. 18 ohms b. 6 ohms c. 12 ohms d. none of the above

C

Two charges that are separated by one meter exert 1-N forces on each other. If the charges are pushed together so the separation is 25 centimeters, the force on each charge will be a. 4 N b. 2 N c. 16 N d. 1 N e. 8 N

C

Two charges that are separated by one meter exert 1-N forces on each other. If the magnitude of each charge is doubled, the force on each charge is a. 2 N b. 1 N c. 4 N d. 8 N e. none of the above

C

Electric potential, measured in volts, is the ratio of electric energy to the amount of electric a. voltage b. current c. resistance d. charge e. none of the above

D

It is said that electric charge is quantized which means that the charge on an object a. may occur in an infinite variety of quantities b. can be neither created nor destroyed c. is sometimes positive d. is a whole-number multiple of the charge of one electron e. will interact with neighboring electric charges

D

The electric field inside the dome of a Van de Graeff generator depends on the a. volume of the dome b. amount of charge and volume of the dome c. amount of external charge d. none of the above

D

The force that binds atoms together to form molecules is a. centripetal b. nuclear c. gravitational d. electrical e. none of the above

D