Electricity - 9 science assessment 1

Question 1

Describe the structure of an atom

Answer 1

Within an atom, there are three subatomic particles which are protons (positive charge), neutrons (neutral or no charge) and electrons (negative charge). Protons and neutrons are in the nucleus (centre) of the atom while the electrons orbit around the outside/ The number of electrons is equal to the number of protons within an atom.

Question 2

Which subatomic particles attract and repel eachother?

Answer 2

Subatomic particles of the same charge repel eachother but particles of the opposite charge attract eachother - proton+proton=no, electron+electron=no, proton+electron=yes (just remember that opposites attract)

Question 3

What is electricity and how does it occur?

Answer 3

Electricity is the flow of electrons (the flow of negative charge). For electricity to occur, an electron must break free from an atom as a result of electrostatic force and it will then flow to another atom and attatch itself to it, ejecting another electron which will then repeat the same process, causing a flow of electrons between atoms.

Question 4

What is static electricity?

Answer 4

Static electricity is the build-up of charge as a result of friction. The static electricity is then released when electrons release and join another atom.

Question 5

Describe a simple circuit and provide an example for the two crucial parts of a circuit

Answer 5

A circuit is a loop of wire that connects and energy source to a user. An example of an energy source is a battery and an example of a user is a light bulb.

Question 6

What does electric current do?

Answer 6

Electric current pushes energy around the circuit through wires.

Question 7

What does the energy user do to the electrons within the circuit?

Answer 7

The energy user converts the electrons into a useful form (for example, a light bulb would turn electrons into light energy)

Question 8

What is electric current measured in?

Answer 8

Electric current is measured in amps (A). The symbol for current is I. (I=2A means current=2amps)

Question 9

What is charge passing wire in a second measured in?

Answer 9

The amount of charge that passes a specific point in the wire in one second is measured in Coulombs which is the quantity of charge.

Question 10

What is the difference between coulombs and amps?

Answer 10

A coulomb measures the quantity of charge (how much charge passes the line in a second) and amps measure the strength of the current. (1 amp=1 coulomb per second)

Question 11

Describe the movement of current within a circuit from a battery

Answer 11

The current exits the battery from the positive side and returns after being distributed back through the negative side.

Question 12

What does an ammeter measure and what unit is it measured in?

Answer 12

An ammeter measures current (I) which is measured in amps (A)

Question 13

What does larger and smaller current mean?

Answer 13

If a circuit has larger current, there is more charge passing the wire in a second resulting in more amps. if there is less current, there’s less charge and less amps.

Question 14

What does resistance do?

Answer 14

Resistance opposes the flow of electric current, slowing down electric current.

Question 15

What is resistance measured in an what is it represented as?

Answer 15

Resistance (R) is measured in Ohms which is shown as an omega symbol.

Question 16

What does high and low resistance mean?

Answer 16

If something has high resistance, it menas that it is harder to flow through and it has more Ohms, resulting in higher voltage drop. If something has low resistance, it’s easy to flow through and has less Ohms, resulting in lower voltage drop.

Question 17

What is voltage drop?

Answer 17

Voltage drop is the energy that has been lost in the process of travelling through the circuit.

Question 18

What is voltage and what is it measured in?

Answer 18

Voltage is the potential energy of a circuit (also known as potential difference). It is measured in volts (V)

Question 19

How is a voltmemeter connected to a circuit and what does it measure?

Answer 19

A voltmeter is connected in parallel and it measures voltage.

Question 20

What happens to potential energy when current flows through the circuit and what is it called?

Answer 20

There is a loss of potential energy when a current flows through a circuit component. This is called voltage drop.

Question 21

What is an Ohmic and Non-ohmic graph?

Answer 21

The graph for a ohmic conductor is a straight line and if the graph is curved, it’s a non-ohmic conductor.

Question 22

Where does potential energy flow from?

Answer 22

One side of a circuit has high potential energy and one has low potential energy. Its flows from high potential energy areas to low potential energy areas.