Electricity Unit Test

Question 1

grounding

Answer 1

process of removing excess charges from and object by contact with Earth (large, neutral object)

Question 2

Electroscope

Answer 2

a device that can be used to detect the presence of an electric charge

Question 3

Electrostatic Series

Answer 3

a list of materials in order of increasing tendency to gain electrons.

Question 4

Static Electricity

Answer 4

The electric charge that builds up on the surface of the object. They stay in that location on the surface of the object until they are given a path to escape.

Question 5

Current Electricity

Answer 5

Continuous flow of electric charges around a closed loop starting and ending at a power source

Question 6

Voltage

Answer 6

is a measurement of the difference in the potential energy before and after(drop)

Question 7

Electric Current

Answer 7

a measure of the amount of electric charge that passes by a point in an electric circuit each second

Question 8

Resistance

Answer 8

the ability to impede (stop) the flow of electrons in a conductor.

Question 9

What facctors affect resistance

Answer 9

Material->conductors-> low R, insulators->high R
Tempratue->high->high R, low->Low R
Length–>longer->high R, shorter->Low R
Thickness->wide-> low R, narrow->high R

Question 10

Ohm’s Law

Answer 10

gives the relationship between current, voltage and resistance
R=V/I
I=V/R
V=IR
All components of a cicuit follow ohm’s law

Question 11

Power

Answer 11

The rate at which electrical energy is converted into another form of energy
P=E/t

Question 12

Efficiency

Answer 12

the measure of how much useful energy an electrical device produces compared to the energy supplied to the device

Question 13

Potential Difference

Answer 13

voltage/the difference of electrical potential between two points.

Question 14

Series Circuit

Answer 14

electrons can follow only one path

Question 15

Parallel Circuit

Answer 15

electrons can flow more than one way because the loads are on at least two different branches

Question 16

Ammeter

Answer 16

A device that meassures current

Question 17

Voltmeter

Answer 17

A device that meassures voltage

Question 18

Load

Answer 18

electrical device, such as a light bulb, that converts electrical energy into another form of energy

Question 19

Energy Source

Answer 19

provides the electrical energy in a circuit

Question 20

Conductor

Answer 20

material that allows electrons to change position easily

Question 21

Insulator

Answer 21

material that resists or blocks the movement of electrons

Question 22

Semi-Conductor/Fair-conductor

Answer 22

allow only some movement of electrons. Electrons do not move as freely as in a conductor, but are not held as tightly in place as in an insulator.

Question 23

Open-Circuit

Answer 23

A circuit in which the continuity is broken due to which the electric current can not flow

Question 24

Closed-Circuit

Answer 24

contains a complete path between the positive and negative terminals of its power source

Question 25

Short Circuit

Answer 25

A circuit that is missing a load to use up the energy

Question 26

Charging by Contact

Answer 26

occurs when a charged object and a neutral object come in contact and electrons move from one object to the other until there is a balanced distribution of charge between the two.

Question 27

Charging by induction

Answer 27

occurs when a charged object charges a neutral object without touching it.

Question 28

Charging by Induction - Temporary

Answer 28

when a charged object is brought near a neutral object if causes (induces) the electrons to shift in position, resulting in an uneven distribution

Question 29

Charging by Induction - Permanent

Answer 29

charge an object permanentlyby induction, you use a charged object to induce a charge in a neutral object. Previously neutral object is then grounded, and now has the opposite charge to the object that was used to charge it

Question 30

Renewable resource

Answer 30

A substance of economic value that can be replaced or replenished in the same amount or less time as it takes to draw the supply down.

Question 31

Nonrenewable Resource

Answer 31

A nonrenewable resource is a natural resource that cannot be re-made or re-grown at a scale comparable to its consumption.

Question 32

Current smybol and unit of measurement

Answer 32

I Ampres(Amps) A

Question 33

voltage smybol and unit of measurement

Answer 33

V Volts V

Question 34

resistance smybol and unit of measurement

Answer 34

R Ohms Ω

Question 35

energy smybol and unit of measurement

Answer 35

E Joules J

Question 36

power smybol and unit of measurement

Answer 36

P Watts W

Question 37

Time smybol and unit of measurement

Answer 37

t seconds s hours h

Question 38

Efficiency smybol and unit of measurement

Answer 38

Eff Percentage %

Question 39

Law of electric charges

Answer 39

Like charges repel Unlike charges attract

Question 40

Charging by friction

Answer 40

When two objects rub together, the force of friction can remove electrons from one object and cause them to transfer to the other. As one object loses electrons, the other gains them, as shown by the amber and the fur.

Question 41

What happens to an object if grounded

Answer 41

If the object is positively charged, the electrons will move into the object from the ground until its neutural If the object is negatively charged, the electrons will leave the object into the ground until its neutural

Question 42

Explain how lightning is made

Answer 42

1. clouds build up a -ve charge 2. electrons in the ground/trees get reppeled by the -ve charge in the clouds 3.electrons will jump from the -ve clouds to the +ve ground due to attraction

Question 43

How do electrons lose energy in a cicuit

Answer 43

The energy provided by the power source(battery) is lost to the load(output) which converts it into another form of energy

Question 44

How are current and voltage affected by series and parallel cicuits

Answer 44

Series: Voltage of the power source is equal to sum of voltage of loads. Current is constant/equal. Parallel: current of the power source is equal to sum of currents through each loop. Voltage is constant/equal.

Question 45

Three non renewable and 3 renewable sources

Answer 45

Renewable:wind,solar,hydroelectricity Non-Renewable:coal,oil,gas

Question 46

What is a purpose of a fuse, cicuit breaker and GFCI

Answer 46

All: prevent fire Fuse: will break an open circuit if too much current Circuit Breaker: Will cause a switch to open a circuit if too much current GFCI: Will cause a switch to open if too much of differing amounts of current

Question 47

Power sources

Answer 47

A device that converst energy into electrical energy

Question 48

Control Devices

Answer 48

A device that can turn a circuit on and off by making it an open and closed circuit