Physics

Question 1

What is the overall charge of atoms?

Answer 1

Atoms have no overall charge (neutral)

This means that the positive and negative charges balance each other out.

Question 2

What charge do electrons carry?

Answer 2

Electrons carry a negative electric charge

Question 3

What charge do protons carry?

Answer 3

Protons carry a positive electric charge

Question 4

What must happen to create an electric current?

Answer 4

Electrons must be separated from the conductor and stick on the insulator.

Question 5

What occurs when electrons build up on an object?

Answer 5

Static charge occurs

Question 6

On what types of materials can static charge build up?

Answer 6

Static charge can only build up on insulators (plastic/wood)

Static charge cannot build on conductors (metals).

Question 7

Why can’t static charge build on conductors?

Answer 7

Conductors allow electrons to flow away, forming an electric current

Question 8

Describe the binding of electrons in insulators.

Answer 8

In insulators, electrons are very tightly bound to their nuclei

Question 9

What happens when a charge enters an electrical field?

Answer 9

It will feel an electric force (e.g. attract or repel)

Question 10

What occurs when an object holding static charge is discharged?

Answer 10

An electric current flows through the air

Question 11

Give examples of conductors and insulators.

Answer 11

Conductors: Metals
Insulators: Plastics, polystyrene

Question 12

What is formed when charge flows from one spot to another?

Answer 12

An electric current

An electric current requires a power supply and a completed circuit.

Question 13

What are the two things required for an electric current?

Answer 13

• Power supply/potential difference
• Completed circuit (switch is closed)

Both elements are essential for the flow of electric current.

Question 14

What instrument is used to measure the current in a circuit?

Answer 14

Ammeter

An ammeter is designed specifically to measure electric current in amperes.

Question 15

What does current measure?

Answer 15

The amount of charge that passes through a point in a conductor per second (A)

Current is expressed in amperes (A).

Question 16

What instrument is used to measure the voltage in a circuit?

Answer 16

Voltmeter

A voltmeter measures the potential difference between two points in a circuit.

Question 17

What causes electrons to move around in a circuit?

Answer 17

They are given energy

Energy can come from various sources, such as a chemical reaction in a battery.

Question 18

What does a chemical reaction in a battery provide to electrons?

Answer 18

Potential energy

This energy is necessary for the movement of electrons in the circuit.

Question 19

What happens to potential energy when a circuit is connected?

Answer 19

It is converted into kinetic energy

This allows electrons to move freely within the wire.

Question 20

What is the difference between two points in a circuit called?

Answer 20

Voltage (V)

Voltage is also referred to as potential difference.

Question 21

How is voltage measured in a circuit?

Answer 21

By connecting a voltmeter before and after a component

This measures the change in potential difference across the component.

Question 22

What is resistance?

Answer 22

A measure of how hard it is for current to flow through a material

Resistance affects the flow of electric current in a circuit.

Question 23

What type of materials have low resistance?

Answer 23

Conductors

Conductors allow current to flow easily.

Question 24

What type of materials have high resistance?

Answer 24

Insulators

Insulators resist the flow of electric current.

Question 25

In what unit is resistance measured?

Answer 25

Ohms ## Footnote The symbol for ohms is Ω; more ohms indicate greater resistance.

Question 26

The more Ohms, the more _______.

Answer 26

resistive ## Footnote Higher resistance means it is harder for current to flow.

Question 27

The ___ the resistance the ___ the current

Answer 27

greater, smaller

Question 28

The ___ the voltage the ___ the current

Answer 28

greater, greater

Question 29

What do resistance and voltage do to the electric current

Answer 29

Resistance tries to slow down the current Voltage tries to "push" the current around the circuit

Question 30

If the graph is Ohmic, it will produce ___

Answer 30

A straight line with a gradient = to 1/R

Question 31

For an electric circuit to work it needs ___

Answer 31

energy

Question 32

The rate at which energy is being used is

Answer 32

Power (P) measured in Watts (W)

Question 33

Power equals

Answer 33

Energy/Time or (Voltage x Current)

Question 34

Charges that flow are

Answer 34

negatively charged electrons

Question 35

A lightbulb is connected to the ... side of a battery. The bulb's filament is connected to the ... side.

Answer 35

Positive Negative

Question 36

In a series circuit, all components of a circuit are ...

Answer 36

connected to form a single loop

Question 37

A parallel circuit has ...

Answer 37

several branching circuits, each with its own components

Question 38

All branches in a parallel circuit share a ...

Answer 38

single power supply

Question 39

In a series circuit, the voltage is ...

Answer 39

split between all components in the circuit | e.g. battery with 12V, 2 lightbulbs along the circuit each have 6V

Question 40

In a parallel circuit, the voltage ...

Answer 40

across each branch in the circuit is the same as that produced by the battery | e.g. battery with 12V, circuit has 2 branches, each branch has 12V

Question 41

What is the current in a series/parallel circuit?

Answer 41

* Series Circuit - Current is the same at all points * Parallel Circuit - Current is split between the branches

Question 42

What will happen in a series ciruit if one bulb breaks?

Answer 42

All the lightbulbs go out

Question 43

What is a magnet?

Answer 43

Anything that produces a magnetic field.