Physics Study Guide Ch 22-25

An electric motor is very similar to A. an electric generator. B. an automobile battery. C. a radio receiver. D. none of the above.

A. an electric generator.

The pair of protons in the nucleus of a helium atom A. attract a pair of orbiting electrons. B. repel orbiting electrons. C. both of these D. neither of these

A. attract a pair of orbiting electrons

An electron and a proton A. attract each other. B. repel each other. C. neither attract nor repel each other.

A. attract each other

Place an iron rod inside a current-carrying coil of wire and you A. increase the strength of the electromagnet. B. have a superconducting magnet. C. a mega plane in the making

A. increase the strength of the electromagnet.

To become a positive ion, an atom must A. lose an electron. B. gain an electron. C. lose a proton. D. gain a proton.

A. lose an electron

Several paper clips dangle from the north pole of a magnet. The induced pole in the bottom of the lowermost paper clip is a A. north pole. B. south pole. C. either of these D. neither of these

A. north pole.

The conventional direction of magnetic field lines outside a magnet are from A. north to south. B. south to north. C. either way

A. north to south.

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

B. alternating current.

Whereas electric charges can be isolated, magnetic poles A. can also. B. cannot. C. gather in clusters. D. none of the above

B. cannot.

Magnetic field lines about a current-carrying wire A. extend radially from the wire. B. circle the wire in closed loops. C. both of these D. neither of these

B. circle the wire in closed loops.

Power is defined as the energy expended per unit of time. When translated to electrical terms, power is equal to A. current multiplied by resistance. B. current multiplied by voltage. C. current divided by time. D. voltage divided by time. E. none of the above

B. current multiplied by voltage.

If you thrust a magnet into a closed loop of wire, the loop will A. rotate. B. have a current in it. C. both of these D. neither of these

B. have a current in it.

The frequency of induced voltage in a wire coil depends on A. the frequency of current producing it. B. how frequently a magnet dips in and out of the coil. C. the number of loops in the coil.

B. how frequently a magnet dips in and out of the coil.

To say that an object becomes electrically polarized means that A. it is electrically charged. B. its charges have been rearranged. C. its internal electric field is zero. D.it is only partially conducting. E. none of the above

B. its charges have been rearranged.

Just as in hydraulic circuits there is water pressure, in electric circuits there is A. current. B. voltage. C. resistance.

B. voltage.

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. zero. B. 5 J. C. 10 J. D. more than 10 J. E. need more information

C. 10 J.

What is the force applied on a 3-C charge located in a place where the electric field is 30 N/C? A. 10 N. B. 30 N. C. 90 N. D. 120 N.

C. 90 N.

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. both of these

The force that acts between a pair of magnetic poles depends on A. magnetic pole strength. B. separation distance. C. both of these D. neither of these

C. both of these

Over geologic history the Earth's magnetic field A. has been relatively stable. B. has increased in strength exponentially. C. has reversed direction many times. D. is unknown.

C. has reversed direction many times.

Heat a copper wire and its electric resistance A. decreases. B. remains unchanged. C. increases

C. increases

Electrons can be transferred from one place to another by the process of A. friction. B. contact, which means touching. C. induction, which means non-touching. D. all of the above E. none of the above

D. all of the above

When a pair of identical lamps are connected in parallel A. voltage across each is the same. B. current in each is the same. C. power dissipated in each is the same. D. all of the above

D. all of the above

When the distance between two charges is halved, the electrical force between them A. is reduced by 1/4. B. halves. C. doubles. D. quadruples. E. none of the above

D. quadruples.

The source of electrons in a simple electric circuit is A. the voltage source. B. energy stored in the voltage source. C. energy released by the voltage source. D. the electrical circuit itself. E. none of the above

D. the electrical circuit itself.

It is correct to say that in electric circuits A. charge flows through a circuit. B. flowing charge is current. C. voltage is applied across a circuit. D. voltage is the ratio of energy per charge. E. all of the above

E. all of the above

A conductor differs from an insulator in that a conductor has more A. electrons than protons. B. protons than electrons. C. energy than an insulator. D. faster moving molecules. E. none of the above

E. none of the above