Test 2

Question 1

Alternating current is normally produced by a

a) generator
b) battery
c) both
d) neither

Answer 1

a) generator

Question 2

the unit of resistance is the

a) coulomb
b) ohm
c) volt
d) joule
e) amp

Answer 2

b) ohm

Question 3

the electric charge on all electrons

a) vary from atom to atom
b) vary from ion to ion
c) are identical

Answer 3

c. are identical

Question 4

the source of electrons lighting an incandescent light bulb is

a. atoms in the light bulb filament
b. the source of voltage
c. the electric outlet
d. the power company
e. the wire leading to the lamp

Answer 4

a. atoms in the lightbulb filament

Question 5

an electron and a proton

a. attract or repel depending on distance
b. repel each other
c. attract each other

Answer 5

c. attract each other

Question 6

the current in the wires of an AC

a. changes direction
b. is nonexistent
c. remains relatively constant
d. changes via the inverse square law
e. none of the above

Answer 6

a. changes direction

Question 7

maximum magnetic force on a current-carrying wire occurs when the wire is

a. in the same direction as the magnetic field
b. at an angle other than 90degrees to the magnetic field direction
c. opposite to the magnetic field direction
d. perpendicular to the magnetic field direction
e. none of the above

Answer 7

d. perpendicular to the magnetic field direction

Question 8

the nucleus of an atom is charged

a. negatively
b. positively
c. both
d. none

Answer 8

b. positively

Question 9

a difference between an insulator and a conductor is that a conductor has more

a. protons than electrons
b. faster moving molecules
c. electrons than protons
d. energy than an insulator
e. none of the above

Answer 9

e. none of the above

Question 10

when a person experiences an electric shock, the origin of the electrons compromising the shock is

a. the ground
b. likely a faulty lamp
c. the person’s own body
d. a power plant
e. the electric field in the air

Answer 10

c. the person’s own body

Question 11

the electric force between charges depends on

a. magnitude of electric charges
b. seperation distance between electric charges
c. both
d. neither

Answer 11

c. both

Question 12

unlike electric charges, magnetic poles cannot be

a. observed
b. located
c. separated

Answer 12

c. separated

Question 13

when a steady voltage is applied to one-half as much resistance, the current is

a. is quadrupled
b. is doubled
c. remains the same
d. is half

Answer 13

b. is doubled

Question 14

if you strip electrons from an atom, the atom becomes

a. negatively charged
b. positively charged

Answer 14

b. positively charged

Question 15

the current in a conducting wire is composed of

a. electrons
b. protons
c. neutrons
d. all or any

Answer 15

a. electrons

Question 16

when a current-carrying wire in a magnetic field experiences no force it is likely

a. parallel to the field lines
b. upside down relative to the field
c. overly insulated
d. all of the above

Answer 16

a. parallel to the field lines

Question 17

to say that electric charge is conserved is to say that electric charge

a. may occur in an infinite variety of quantities
b. will interact with neighboring electric charges
c. can neither be created nor destroyed
d. is a whole-number multiple of the charge of one electron

Answer 17

c. can neither be created or destroyed

Question 18

when the distance between two charges is halved, the electric force between the charges

a. doubles
b. quadruples
c. is half
d. is reduced by one-quarter
e. noen of the above

Answer 18

b. quadruples

Question 19

two charged particles near each other are released. as they move, the coulomb’s law electric force on each particle increases. therefore, the particles have

a. not enough information
b. opposite kinds of charge
c. the same kind of charge

Answer 19

b. opposite kinds of charge

Question 20

when a magnet is moved near a loop of wire

a. a voltage is induced in the wire
b. current is made to flow in the loop of wire
c. electromagnetic induction occurs
d. all of the above

Answer 20

d. all of the above

Question 21

the number of protons in the nucleus of an electrically neutral atom is equal to the number of

a. electrons that surround the nucleus
b. neutrons in the nucleus
c. both
d. neither

Answer 21

a. electrons that surround the nucleus

Question 22

electric potential energy is measured in units of

a. volts
b. watts
c. joules
d. amperes
e. any or all

Answer 22

c. joules

Question 23

a device that converts EPE to KE is a

a. transformer
b. motor
c. magnet
d. generator
e. none of the above

Answer 23

b. motor

Question 24

a pair of positively charged plastic straws tend to

a. repel each other
b. neutralize each other
c. attract each other

Answer 24

a. repel each other

Question 25

break a bar magnet in half and each half is a. no longer magnetized b. a magnet with a single pole c. a magnet with a N and S pole

Answer 25

c. a magnet with a N and S pole

Question 26

compared to the mass of a proton, the mass of the electron is a. very much less b. identical c. greater

Answer 26

a. very much less

Question 27

an ampere is a unit of electric a. resistance b. current c. energy d. all of the above e. none of the above

Answer 27

b. current

Question 28

a magnetic field exists in a current-carrying coil of wire a. if it contains a piece of iron b. only if the current changes c. with or without a contained piece of iron

Answer 28

c. with or without a piece of iron

Question 29

a negatively charged balloon touching a wooden wall a. pulls positive charge on the wall surface toward it b. polarizes molecules in the wall c. pushes negative charge in the wall away from it d. all of the above

Answer 29

d. all of the above

Question 30

Like kinds of magnetic poles repel while unlike kinds of magnetic poles a. attract b. repel also c. may attract or repel

Answer 30

a. attract

Question 31

when the voltage across a steady resistance is doubled, the current a. is doubled b. is quadrupled c. is half d. remains the same

Answer 31

a. is doubled

Question 32

electrons will flow in an electric circuit when a. there is a voltage b. electric devices in the circuit are not defective c. electric resistance is low d. the circuit is grounded

Answer 32

a. there is a voltage

Question 33

when you remove electrons from a metal cup, the cup becomes a, negatively charged b. positively charged c. ionized

Answer 33

b. positively charged

Question 34

electric potential is measured in units of a. joules b. amperes c. volts d. watts e. any or all

Answer 34

c. volts

Question 35

to say that an object is electrically polarized is to say a. it is to some degree magnetic b. it is only partially conducting c. its charges have been separated d. its internal EPE is zero e. it is electrically charged

Answer 35

c. its charges have been separated

Question 36

the electric force between charges is strongest when the charges are a. close together b. far apart c. neither

Answer 36

a. close together

Question 37

to say a current is DC is to say that current in the circuit a. is parallel to the connecting wires b. alternates only slowly c. has a single direction

Answer 37

c. has a single direction

Question 38

a device that converts KE to EPE is a a. motor b. generator c. transformer d. magnet e. none of the above

Answer 38

b. generator

Question 39

a 100N box and a 200N box are hoisted the same distance. raising the heavier box requires a. twice as much work b. less work c. four times as much work d. as much work e. more than four times as much work

Answer 39

a. twice as much work

Question 40

stretch a copper wire so that it is thinner and the resistance between its ends a. remains unchanged b. decreases c. increases

Answer 40

c. increases

Question 41

charge carriers in a metal are electrons rather than protons because electrons are a. smaller b. loosely bound c. negative d. all e. none

Answer 41

b. loosely bound

Question 42

electrical resistance is greater for a. wet skin b. dry skin c. both are the same

Answer 42

b. dry skin

Question 43

an electromagnet consists of a a. bar magnet that carries an electric current b. coil of wire c. current-carrying coil with a piece of iron inside

Answer 43

c. current-carrying coil with a piece of iron inside

Question 44

when the current in a wire is reversed, the direction of the surrounding magnetic field a. also reverses b. remains steady c. collapses

Answer 44

a. also reverses

Question 45

the source of all magnetism is a. tiny bits of iron b. aligned atoms c. moving electric charge d. ferromagnetic materials

Answer 45

c. moving electric charge