Physical Science Exam 8

Front 1

V=I x R

Back 1

Ohm''s Law

Front 2

continuous flow of electric charg

Back 2

electric current

Front 3

the difference in electrical potential energy between two places in an electric field

Back 3

voltage

Front 4

device that converts chemical energy to electrical energy

Back 4

battery

Front 5

material that has almost no resistance when cooled to a low temperature

Back 5

superconductor

Front 6

material through which charge cannot easily flow

Back 6

electrical insulator

Front 7

a flow of electrical charge that regularly reverses direction

Back 7

alternating current

Front 8

opposition to the flow of charges in a material

Back 8

resistance

Front 9

Material through which charge can easily flow

Back 9

electrical conductor

Front 10

electrical charge that flows only in one direction

Back 10

direct current

Front 11

True or False

Because a proton is almost 2000 times larger than an electron, the absolute charge of a proton is almost 2000 times greater than that of an electron

Back 11

False

Front 12

True or False

Electric force is a force of attraction or repulsion between electrically charged objects.

Back 12

True

Front 13

True or False

The law of conservation of charge states that the total electric charge in an isolated system is constant

Back 13

True

Front 14

True or False

The direction of current in an electric circuit is defined as the direction in which positive charges would flow.

Back 14

True

Front 15

True or False

The circuits in homes are mostly wired in parallel

Back 15

True

Front 16

True or False

Electric power is calculated by multiplying voltage time current

Back 16

False

Front 17

True or False

Electric power is often measured in kilowatts (1000 W)

Back 17

True

Front 18

True or False

Correct wiring alone is enough to prevent electrical accidents

Back 18

False

Front 19

True or False

The controlled flow of electrons through a circuit gives information in the form of an electrical signal.

Back 19

True

Front 20

True or False

In p-type semiconductors, it appears as though positive charge flows

Back 20

True

Front 21

True or False

Earth's geographic and magnetic poles are the same.

Back 21

False

Front 22

True or False

Not all ferromagnetic materials are magnets

Back 22

True

Front 23

True or False

Electricity and magnetism are different aspects of electromagnetic force.

Back 23

True

Front 24

True or False

Since an electric current could create a magnetic field, Faraday hypothesized that a magnetic field should be able to create electric current

Back 24

True

Front 25

True or False

Electromagnetic induction of an electric current does not require a completed circuit

Back 25

False

Front 26

True or False

A magnet can have just one pole

Back 26

False

Front 27

True or False correct the bold word if false

Doubling the distance between charged particles makes the force between the particles one-fourth as great.

Back 27

True

Front 28

True or False correct the bold word if false

Another name for potential difference is resistance

Back 28

False - voltage

Front 29

True or False correct the bold word if false

A completed loop of conducting material with a source of electrical energy in it is an electric circuit

Back 29

True

Front 30

True or False correct the bold word if false

If in one part of a circuit fails in a parallel circuit, none of the parts of the circuit can function

Back 30

False series

Front 31

True or False correct the bold word if false

In the United States, most households have circuits that are 240 V.

Back 31

True

Front 32

True or False correct the bold word if false

Analog signals encode information as as a series of 1s and 0s

Back 32

False Digital

Front 33

True or False correct the bold word if false

A stationary magnetic field induces voltage in a conductor

Back 33

False moving

Front 34

True or False correct the bold word if false

A transformer is a device that increases or decreases the voltage and current of two linked DC circuit

Back 34

False AC

Front 35

When you walk across a carpet, charge is built up by

a) friction

b) contact

c) induction

Back 35

A Friction

Front 36

Which of the following is a good electrical conductor?

a) wood

b) plastic

c) rubber

d) copper

Back 36

Copper

Front 37

Which of the following does not affect electrical resistance?

a) color

b) thickness

c) length

d) temperature

Back 37

Color

Front 38

Circuits can be opened by which of the following?

a) a fuse

b) a circuit breaker

c) a ground-fault circuit interrupter

d) all of these

e) none of these

Back 38

All of these

Front 39

Like magnetic poles

a) attract each other

b) repel each other

c) neither attract nor repel each other

Back 39

Repel each other

Front 40

A magnetic field is strongest

a) at the north pole

b) at the south pole

c) in the middle of the magnet

d) at both poles

Back 40

At both poles

Front 41

Magnetic field lines begin at

a) both poles and extend to the middle of the magnet

b) the middle of the magnet and extends to the poles

c) the north pole and extend to the south pole

d) the south pole and extend to the north pole

Back 41

C the north pole and extend to the south pole

Front 42

Which of the following does not affect the strength of an electromagnet

a) the direction of the current in the solenoid

b) the type of ferromagnetic core

c) the number of loops in the coil in the solenoid

d) the strength of the current flowing through the wire

Back 42

A the direction of the current int he solenoid

Front 43

The purpose of step-up transformer is to

a) increase voltage and increase current

b) increase voltage and decrease current

c) decrease voltage and decrease current

d) decrease voltage and increase current

Back 43

B Increase voltage and decrease current