Electricity

Question 1

What is current?

Answer 1

Current involves electrons which can carry current as they are free to move within the metal. It is the flow of electrical charge

Question 2

What is current measured in

Answer 2

Amperes (A)

Question 3

What is potential difference?

Answer 3

The amount of electrical work that is done by a cell - voltage.

Question 4

What is potential difference measured in?

Answer 4

Volts (V)

Question 5

What is charge

Answer 5

The amount of electricity travelling in a circuit

Question 6

What is charge measured in?

Answer 6

Coulombs (C)

Question 7

What is the equation for charge?

Answer 7

Charge = current X time

Question 8

What is a series circuit?

Answer 8

A circuit with one loop

Question 9

What is a parallel circuit?

Answer 9

A circuit with two or more loops

Question 10

What is the current like in a series circuit?

Answer 10

The current is the same in all components

Question 11

What is the current like in a parallel circuit?

Answer 11

The total current is the sum of each components current.

Question 12

What is the potential difference (voltage) like in a series circuit?

Answer 12

The total potential difference from the battery is shared between all the components

Question 13

What is the potential difference (voltage) like in a parallel circuit?

Answer 13

The potential difference across all the components is the same

Question 14

What is the resistance like in a series circuit?

Answer 14

The total resistance is the sum of each components resistance

Question 15

What is the resistance like in a parallel circuit?

Answer 15

The total resistance is less than the resistance value of the smaller individual resistor

Question 16

How do you work out the total potential difference in a series circuit?

Answer 16

If cells are joined, add up all the individual cell values

Question 17

What is the equation for resistance?

Answer 17

Potential difference / current

Question 18

How is an ammeter set up in relation to components?

Answer 18

In series with the components

Question 19

How is a voltmeter placed in relation to components

Answer 19

Set up parallel to components

Question 20

What is resistance?

Answer 20

A measurement of how much current flow is reduced

Question 21

The higher the resistance, the more ________ it is for current to flow

Answer 21

Difficult

Question 22

What happens to current when resistance is increased?

Answer 22

It is reduced

Question 23

What happens to current when voltage is increased?

Answer 23

Current is increased

Question 24

Work is done when..

Answer 24

Charge flows

Question 25

What are the two equations for power?

Answer 25

Power = (current) ² x resistance Power = potential difference x current

Question 26

What is the equation for energy transferred?

Answer 26

Power x time

Question 27

How can current be altered?

Answer 27

Changing the potential difference of the cells and adding more components.

Question 28

What so step up transformers do?

Answer 28

They increase voltage and decrease current as well as increasing efficiency which reduces heat loss

Question 29

What do stepdown transformers do?

Answer 29

They decrease voltage and increase current, making the electricity safer to use in houses

Question 30

What happens to resistance when temperature is increased in a thermistor?

Answer 30

The resistance decreases

Question 31

What happens to the resistance when light increases in a LDR?

Answer 31

The resistance decreases

Question 32

How is a diode represented on a graph?

Answer 32

It is represented by a single curve passing through the origin in the second quadrant. Current only passes one way

Question 33

How is Ohm’s law shown on a graph?

Answer 33

It is a single straight line - the current is directly proportional to the potential difference across the resistor.

Question 34

How is a filament lamp shown on a graph?

Answer 34

It is a curvy line through the origin. As current increases, resistance increases, the temperature increases as current flows