P4 - electricity

Question 1

What are the charges for protons, neutrons and electrons?

Answer 1

+1 0 -1

Question 2

Opposite charges…

Answer 2

Attract

Question 3

Same charges…

Answer 3

Repel

Question 4

A charged object creates an electric field around it. A second charged object in that field experiences a _______ because of this.

Answer 4

Force

Question 5

The closer the objects, the ________ the force between them

Answer 5

Stronger

Question 6

What type of force is this?

Answer 6

A non-contact force (do not need to touch)

Question 7

What can be transferred between atoms?

Answer 7

Electrons

Question 8

Electrons can be moved via…

Answer 8

Friction

Question 9

When you rub one _____ onto another, electrons are transferred

Answer 9

Insulator

Question 10

What does a cell do?

Answer 10

Provides the circuit with a source of potential difference

Question 11

What does a voltmeter do?

Answer 11

Used to measure the potential difference of a component

Question 12

What does an ammeter do?

Answer 12

Used to measure the current in a circuit

Question 13

How is a voltmeter connected?

Answer 13

In parallel with the component

Question 14

How is an ammeter connected

Answer 14

In series with other components

Question 15

What is a fixed resistor?

Answer 15

A resistor limits the flow of current. A fixed resistor has a resistance it cannot change

Question 16

What is a thermistor?

Answer 16

The resistance of a thermistor depends on the temperature. As temperature increases the resistance decreases.

Question 17

What is a variable resistor?

Answer 17

A resistor with a slider that can be used to change its resistance

Question 18

What does LDR stand for and what does it do?

Answer 18

Light dependent resistor - it changes its resistance depending on the light intensity

Question 19

What does LED stand for and what does it do?

Answer 19

Light emitting diode - emits light when a current passes through it

Question 20

What is a diode?

Answer 20

A component that allows current to flow in one direction only

Question 21

An electric current is a flow of…

Answer 21

Charge

Question 22

Only _______ move, which carry a ________ charge

Answer 22

Electrons, negative

Question 23

The size of the current is the _____ of flow of charge (flow of charge per second)

Answer 23

Rate

Question 24

Why are metal good conductors?

Answer 24

They contain free electrons that can move between the positively charged metal ions.

Question 25

What is the difference between a battery and a cell?

Answer 25

A battery contains multiple cells

Question 26

What is the formula for current? (Letters not words)

Answer 26

Q = I x T

Question 27

What is the formula for current? (Words not letters)

Answer 27

Charge = Current x Time

Question 28

What is current measured in?

Answer 28

Amps (A)

Question 29

A circuit has a current of 0.25 A which passes through a filament bulb. Calculate the charge that passes through the bulb in 1 minute.

Answer 29

15 C

Question 30

9000 C of charge flows through a light bulb in 5 hours. What is the current?

Answer 30

0.5 A

Question 31

We use cells to move ______ around a circuit

Answer 31

Charge

Question 32

What is the formula for voltage (potential difference)

Answer 32

Voltage = Energy transferred / Charge
Or
E = QV

Question 33

What is potential difference measured in?

Answer 33

Volts (V)

Question 34

Electrons passing through a wire have to push through lots of vibrating _____ in the metal. This is called _________.

Answer 34

Atoms, resistance

Question 35

In a wire with high resistance, the energy from the _______ trying to pass through is transferred into other stores of energy, such as _______.

Answer 35

Electrons, heat

Question 36

What is the formula for resistance?

Answer 36

Resistance = potential difference / current
Or
V = IR

Question 37

What is resistance measured in?

Answer 37

Ohms (Ω)