The Basics
What is electricity?
What is voltage?
The electric push/force that drives electrons through a circuit.
What is resistance?
Resistance is how much a component or material opposes the flow of current.
What is the symbol for a lightbulb?
Teacher to decide
What is an example of an electrical hazard?
Damaged wire
Water near electricity
Overloaded power-boards
Exposed metal becoming live
What is the charge of an electron?
It is negative.
If the formula for working out voltage is V = I x R, what is the rearranged formula to work out resistance?
R = V / I
What is the difference between a variable resistor and a fixed resistor?
A variable resistor allows you to control the strength of current flowing, whereas a fixed resistor has a fixed flow of current.
What is the difference between a series and parallel circuit?
A series circuit only has one path, whereas a parallel circuit has two or more pathways for the current to travel.
What is an example of double insulation?
A phone charger
Kitchen appliances
Power tools
What is the difference between static electricity and current electricity?
Static electricity is made from a build of charges and current electricity is the flow of electric charges.
If a circuit has a current of 3A and a resistance of 4 ohms, what is the voltage?
Use the formula V = I x R
Provide full working out.
V = I x R
V = 3 x 4
V = 12V
What is a factor that affects resistance?
Length of wire
Thickness of wire
Material of wire
Temperature
A group of two or more cells is called?
A battery.
What is earthing?
Earthing is a safety method where a piece of metal that is connected to wires is placed into the ground.
Is sea water a conductor or insulator?
It is a conductor.
If a circuit has a voltage of 10V and a current of 2A, what is the resistance?
Rearrange and use the formula V = I x R
Provide full working out.
V = I x R
R = V / I
R = 10 / 2
R = 5 ohms
What is the total resistance of three resistors in series, one has 2 ohms, one has 4 ohms and one has 5ohms?
Use the formula:
RT = R1 + R2 + R3
RT = R1 + R2 + R3
RT = 2 + 4 + 5
RT = 11 ohms
Parallel Circuits as the multiple pathways allow for power to stay on if one light goes out.
What is a circuit breaker?
A resettable safety switch that cuts off electricity when current becomes too high.
What is the Particle Model?
The Particle Model suggests that all matter is made up of tiny particles that are constantly moving and attracting one another.
In a circuit, what happens to the current when resistance is increased?
When resistance increases, current decreases.
What is the total resistance of three resistors in parallel, each resistor has a resistance of 4 ohms?
Use the formula:
RT = R / number of R
or
1 / RT = 1 / R1 + 1 / R2 + 1 / R3
RT = R / number of R
RT = 4 / 3
RT = 1 and 1 / 3 ohms ( or 1.33 ohms)
What does an ammeter do?
Measures current.
Why do power-boards over heat and what happens?
There are too many appliances drawing electricity out at the same time, therefore too much current is flowing through the circuit. This overheats the wires and increases the risk of electrical hazards.