Vocabulary

Question 1

static electricity

Answer 1

a charge produced
by rubbing or touching objects
together

Question 2

Law of Charges

Answer 2

Laws that describe
the behaviour between charged and
uncharged objects:
1. Unlike charges attract
2. Like charges repel
3. Charged objects attract uncharged
(neutral) objects

Question 3

Insulators

Answer 3

any material in which the
charge stays on the spot where the
object is rubbed; most non-metals
are insulators

Question 4

conductors

Answer 4

materials that allow
charges to move freely; most metals
are conductors

Question 5

Superconductor

Answer 5

materials that offer
little or no resistance to the flow of
charges

Question 6

discharge

Answer 6

the re balancing of
an unbalanced charge; felt as a shock
or seen as a spark

Question 7

Circuit

Answer 7

path for transmitting electric current.

Question 8

Battery

Answer 8

a combination of cells, either

wet or dry

Question 9

galvanometer

Answer 9

an instrument used to

measure very weak current

Question 10

ammeter

Answer 10

an instrument used to measure larger currents

Question 11

ampere

Answer 11

the unit used to measure
electric current (A). Milliamperes
(mA) is also commonly used

Question 12

potential difference

Answer 12

the difference
in potential energy per unit of charge
between one point in the circuit and
another point in the circuit

Question 13

voltmeter

Answer 13

the instrument used to

measure voltage

Question 14

resistance

Answer 14

the property of a substance that hinders motion of electric charge and converts electric energy into other forms of energy

Question 15

ohmmeter

Answer 15

an instrument to directly measure resistance

Question 16

current

Answer 16

a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space

Question 17

series circuit

Answer 17

circuits with only one current path

Question 18

parallel circuit

Answer 18

circuits with several current paths

Question 19

Thermocouple

Answer 19

a loop of two wires
made of different types of metals that
converts heat to energy

Question 20

thermo-electric generator

Answer 20

plants that burn fossil fuels to produce

electricity

Question 21

piezoelectric effect

Answer 21

sound produced
when an electric current causes
vibrations in a tiny crystal

Question 22

photovoltaic cell

Answer 22

a device used
to produce electricity
from light

Question 23

electrochemical

Answer 23

device that can generate electrical energy from the chemical reactions occurring in it, or use the electrical energy supplied to it to facilitate chemical reactions in it

Question 24

electrode

Answer 24

the two metals in a

voltaic or electrochemical cell

Question 25

electrolyte

Answer 25

a substance that conducts an electric current, and in which the electrodes are placed

Question 26

primary cell

Answer 26

an electric cell that produces current by an irreversible chemical reaction.

Question 27

secondary cell

Answer 27

A rechargeable electric cell that converts chemical energy into electrical energy by a reversible chemical reaction

Question 28

electric generator

Answer 28

a device that converts mechanical energy into electric energy

Question 29

electromagnet

Answer 29

a strong temporary magnet, created by inserting a soft iron core into a coil of wire and then passing a current through the wire

Question 30

alternating current

Answer 30

electricity produced in a generator where the current flowing from the generator changes direction regularly

Question 31

direct current

Answer 31

current that | flows in one direction only

Question 32

dynamo

Answer 32

a generator that produces | direct current

Question 33

split-ring commutator

Answer 33

two metal half rings connecting either end of the rotor coils to the brushes.

Question 34

stator

Answer 34

a stationary part of a motor surrounding the rotor. The simplest form of stator is a two-pole electromagnet

Question 35

transformer

Answer 35

used to “step-up” the voltage for efficient transmission of current over long distances

Question 36

circuit breaker

Answer 36

acts as a switch and safety device that can cut all power coming into the home

Question 37

fuse

Answer 37

a device containing a metallic conductor that melts when heated by excessive current

Question 38

Neutral wire

Answer 38

``` one of the “live” wires in electric cables, which returns low energy electricity back to the breaker panel; the neutral wire is white and insulated ```

Question 39

hot wire

Answer 39

one of the “live” wires in electric cables, which carries high energy electricity; the hot wire is black and insulated

Question 40

ground wire

Answer 40

a device to safely channel any energy that has “leaked” out; the ground wire is either bare copper or covered with green insulation

Question 41

transistor

Answer 41

electronic switches in | modern digital devices

Question 42

power(formula)

Answer 42

energy per unit time. | Power Energy/Time

Question 43

watt

Answer 43

a unit of power equivalent | to one joule per second; 1 W = 1 J/s

Question 44

electrical code

Answer 44

the set of standards | for electrical work

Question 45

electrical efficiency

Answer 45

efficiency = energy out energy in × 100 %.

Question 46

short circuit

Answer 46

occurs when the wires in an electric cord accidentally connect, usually because of frayed insulation

Question 47

non-renewable resource

Answer 47

fuels that are consumed faster than they can be replaced by nature

Question 48

hydroelectricity

Answer 48

Hydroelectricity, or hydroelectric power, is electricity produced from hydropower.

Question 49

co generator system

Answer 49

electricity generating stations that produce electricity and also supply thermal energy

Question 50

solar energy

Answer 50

radiant energy emitted by the sun.

Question 51

geothermal energy

Answer 51

thermal energy contained in the inner portions of Earth

Question 52

thermal pollution

Answer 52

occurs when warm water is returned directly to the lake or river from where it is taken, increasing the water temperature