Electricity

Question 1

Current

Answer 1

The amount of electrical charge that is transferred per second

Question 2

The amount of electrical charge that is transferred per second

Answer 2

Current

Question 3

What is current measured in?

Answer 3

Amperes (A)

Question 4

Relationship between current, charge, and time

Answer 4

charge = current x time, or Q = It

Question 5

Coulomb

Answer 5

Unit for charge, a group of electrons

Question 6

Unit for charge, a group of electrons

Answer 6

Coulombs

Question 7

Conductors

Answer 7

Materials that allow electrical current to flow freely

Question 8

Materials that allow electrical current to flow freely

Answer 8

Insulators

Question 9

Materials that make it difficult for charges to move

Answer 9

Insulators

Question 10

Insulators

Answer 10

Materials that make it hard for charges to move

Question 11

How do charges move in a circuit?

Answer 11

They are given energy in the supply, this is energy is transformed in components in the circuit

Question 12

Potential difference

Answer 12

The difference in electrical potential between two points

Question 13

Voltage is the…

Answer 13

Energy given to each coulomb of charge

Question 14

Electrons are attracted to…

Answer 14

Protons

Question 15

Electrons flow from…

Answer 15

The negative terminal to the positive terminal

Question 16

DC current

Answer 16

Where the current will only flow in one direction around a circuit (from negative to positive)

Question 17

AC current

Answer 17

The voltage changes between positive and negative continually, so the charges periodically change direction

Question 18

Resistance

Answer 18

A measure of how much opposition there is to the current in a circuit

Question 19

Measure of the opposition to current in a circuit

Answer 19

Resistance

Question 20

Resistance in a series circuit

Answer 20

The current moves through all resistors and components, so experiences all resistance

Question 21

Resistance in a parallel circuit

Answer 21

Each part of the circuit acts a tunnel for current to move through, but there is less resistance because less current moves through each resistor

Question 22

Ohm’s Law

Answer 22

The relationship between current and voltage, as well as resistance

Question 23

The relationship between current and voltage, as well as resistance

Answer 23

Ohm’s Law

Question 24

What does Ohm’s Law show?

Answer 24

Voltage is directly proportionate to current, and V/I = R

Question 25

What has to remain constant for a component to be considered "ohmic"?

Answer 25

Temperature

Question 26

How does temperature affect resistance

Answer 26

As temperature increases, so does resistance

Question 27

Potential divider

Answer 27

A circuit where each each resistor takes a proportion of the supply voltage

Question 28

What does the proportion of a potential divider rely on?

Answer 28

The size of each resistor and the total resistance in the circuit

Question 29

Formula for potential dividers

Answer 29

V1/V2 = R1/R2

Question 30

Capacitor

Answer 30

An electrical component that stores electrical charge, the voltage across it is equal and opposite to the supply voltage when fully charged

Question 31

Thermistor

Answer 31

A resistance where the resistance increases as the temperature decreases (TURD)

Question 32

Light dependant resistor (LDR)

Answer 32

A resistor where increasing light levels decreases resistance (LURD)

Question 33

Light Emmiting Diode (LED)

Answer 33

A diode that only allows current to flow in one direction | On a circuit diagram the point MUST face the negative terminal

Question 34

Photovoltaic cell

Answer 34

Converts light energy into electrical energy

Question 35

Motor

Answer 35

Converts electrical energy into kinetic energy

Question 36

Loudspeaker

Answer 36

Converts electrical energy into sound energy

Question 37

Relay

Answer 37

An electromechanical switch where applying a small voltage to the iput with switch on/off a larger current or voltage in a seperate circuit

Question 38

Transistor

Answer 38

An electronic switch that works by applying a voltage between the base and emitter (it makes it conduct through the emitter and collector)

Question 39

Voltage required to switch on a transistor

Answer 39

0.7V or more

Question 40

Application of transistors

Answer 40

Used in potential divider circuits to provide voltage to the transistor when the light levels or temperature are high/low enough

Question 41

Electrical power

Answer 41

The amount of energy transformed per second

Question 42

How does power relate to current and voltage

Answer 42

IV can be turned into E/Q x Q/t, so E/t (IV = E/t)

Question 43

Formulae for power

Answer 43

P =... E/t, IV, I^2R, V^2/R