Electricity Key Words

Question 1

Electron

Answer 1

Negatively charged sub-atomic particle

Question 2

Electron flow

Answer 2

The movement of electrons (usually around a circuit), from - to +

Question 3

Insulator

Answer 3

A material with a small number density of conduction electrons and therefore a high resistance

Question 4

Internal resistance

Answer 4

The resistance of a battery or cell, measured in ohms

Question 5

I-V Characteristic

Answer 5

A graph to show how the electric current through a component varies with the potential difference across it.

Question 6

Kirchhoff’s first law

Answer 6

The sum of the currents entering any junction is equal to the sum of the currents leaving the junction

Question 7

Kirchhoff’s second law

Answer 7

The sum of the e.m.f.s is equal to the sum of the p.d.s in a closed loop

Question 8

LDR

Answer 8

A component that changes its resistance with changes in light intensity

Question 9

LED

Answer 9

A component that only allows electric current to pass in one direction and that emits light when p.d. is applied across it

Question 10

Ohm’s law

Answer 10

The electric current through a conductor is proportional to the potential difference across it, provided that physical conditions, such as temperature, remain constant

Question 11

Parallel circuit

Answer 11

A type of circuit where the components are connected in 2 or more branches and therefore provide more than 1 path for the electric current

Question 12

Potential difference

Answer 12

The electrical energy transferred per unit charge when electrical energy is converted into some other form of energy

Question 13

Potential divider

Answer 13

A type of circuit containing 2 components designed to divide up the p.d. in proportion to the resistances of the components

Question 14

Resistance

Answer 14

A property of a component that regulates the flow of current through it

Question 15

Resistivity

Answer 15

The ratio of the product of resistance and cross-sectional area of a component to its length

Question 16

Series circuit

Answer 16

A type of circuit where the components are connected end to end and therefore provide only one path for the electrical current

Question 17

Thermistor

Answer 17

A component that changes its resistance depending on its temperature

Question 18

Volt

Answer 18

The unit of p.d. and e.m.f.

Question 19

Components

Answer 19

Parts of electric circuits l, including bulbs, LDRs, thermistors etc.

Question 20

Conductor

Answer 20

A material with a high number density of conduction electrons and therefore low resistance

Question 21

Conventional current

Answer 21

A model used to describe the movement of charge in a circuit travelling from + to -

Question 22

Coulomb

Answer 22

Unit of electrical charge (C)

Question 23

Efficiency

Answer 23

The ratio of useful output energy to total input energy

Question 24

Electric current

Answer 24

A flow of charge

An SI quantity, measure in amperes; a vector quantity

Question 25

Electrolyte

Answer 25

A fluid that contains ions that are free to move and hence conduct electricity

Question 26

E.M.F

Answer 26

The electrical energy transferred per unit charge when one form of energy is converted into electrical energy, measured in volts