Circuits

Question 1

Current

Answer 1

Flow of electrons in a circuit, carries electrical energy to components

Question 2

Current in series

Answer 2

Same at all points in circuit - not used up

Question 3

Current in parallel

Answer 3

The current in branches adds up to the total leaving and returning to the cell.
The current splits down each branch

Question 4

Potential difference

Answer 4

A measure of how much energy is transferred in different parts of the circuit
Basically the energy to push the current around

Question 5

Potential difference in series

Answer 5

The total V in all components = the voltage in the cell

Question 6

Potential difference in parallel

Answer 6

Total voltage in each branch is the same

Question 7

Potential difference in a battery

Answer 7

All the cells added up together, if some are facing the wrong way they cancel it out.

Question 8

Resistance

Answer 8

The opposition to the flow of current (slows it down)

Question 9

Resistance in series

Answer 9

Increases as more components are added

Question 10

Resistance in parallel

Answer 10

Decreases as more components are added, because there are more paths for the current to pass through.

Question 11

Charge

Answer 11

The property of being charged
A current of 1 ampere = 1 coulomb of charge flowing per second

Question 12

Charge, energy and voltage?

Answer 12

Energy transferred = Charge flow × Potential difference
E = Q x V
Evil Queen Vacuuming

Question 13

How to find the charge flow?

Answer 13

Charge flow = current x time
Q = I x T
(Queen It’s Time)

Question 14

Resistor

Answer 14

Adds resistance to the electrical circuit
less energy is transferred per current

Question 15

If the resistance is kept constant, what happens to the current and potential difference?

Answer 15

They will increase proportionally as long as the temp is the same

Question 16

Fuse

Answer 16

Made up of thin wire that melts if too much current goes through

Question 17

LDR

Answer 17

Light dependent resistor
Resistor affected by light hitting it

Question 18

LED

Answer 18

Light emitting diode
Produce light when a current flows through them in the forward direction

Question 19

Diode

Answer 19

Component that regulates potential difference
Resistance is high in one direction so current can only flow through the OTHER direction

Question 20

What way does the current flow in a circuit?

Answer 20

From the negative end to the positive

Question 21

When electrons return to the positive end what happens to the energy?

Answer 21

They have less energy than they did before they left the cell

Question 22

Conventional current

Answer 22

Incorrect idea scientists and the electrons went from positive end to negative end
We still draw arrows like this however

Question 23

Unit of current

Answer 23

Ampere (A)

Question 24

How to measure current?

Answer 24

Use an ammeter

Question 25

How is potential difference, charge and energy transferred linked?

Answer 25

1 volt means 1 joule of energy is transferred per coulomb of charge

Question 26

How to measure voltage?

Answer 26

Voltmeter

Question 27

Why are lamps dimmer when more lamps are connected in series?

Answer 27

Because voltage in series splits evenly so more added = less voltage for one lamp = less energy transferred to light energy

Question 28

Ohm’s law

Answer 28

The current and potential difference is directly proportional as long as certain conditions are kept the same

Question 29

Factors effecting ohms law?

Answer 29

These must be kept constant: Resistance

Question 30

Current in an ohmic resistor

Answer 30

Directly proportional to voltage Because resistance doesn’t change when current is in creased (If the temp is constant)

Question 31

What must the ohmic resistor be for this law to work?

Answer 31

Temperature is kept constant

Question 32

Why does adding more components in series decrease the energy transfer for each one?

Answer 32

Because in series the voltage in the battery is equal to the total voltage of components So adding more components means you’ll have to share the voltage between them Thus less energy transferred to them per coulomb of charge

Question 33

Current and potential difference through a resistor

Answer 33

Directly proportional

Question 34

Thermistor

Answer 34

Resistance depends upon the temperature

Question 35

Variable resistor

Answer 35

Can change the resistance = not set

Question 36

What does the potential difference/ current graph look like for a variable resistor?

Answer 36

Directly proportional Because of Ohm’s law that they will be kept constant

Question 37

What does the potential difference/ current graph look like for a Diode?

Answer 37

Almost 0 in negative values Then becomes increasing after that like a curve Because it has very high resistance in negative direction = no current