Applied Science Unit 3: Electricity

How can energy be calculated?

Heat of combustion (kJ mol-1) = ((heat energy to water (kJ) × relative molecular mass of fuel)) / mass of fuel burnt (g).

What is a battery in a circuit?

Made up of more than one cell.

What is an ammeter in a circuit?

It measures current through a component; placed in series.

What is a voltmeter in a circuit?

It measures voltage across a component; placed in parallel.

What is a bulb in a circuit?

A component that produces light when current flows.

What is a resistor?

A component that controls current in a circuit.

What is a variable resistor?

Used to change current in a circuit; placed in series.

What is a diode?

Allows current to flow in only one direction; placed in series.

What is power?

Rate of doing work; energy used per unit time.

What can power refer to?

Physical work or electrical power.

What does work done equal?

Work done = energy supplied or transformed.

What is the equation for electrical power?

Power = voltage × current (P = VI).

What is the equation for physical power?

Power = work done ÷ time (P = W/t).

What is a fuse?

A safety component that melts ('blows') if there is a fault in the circuit.