Year 9 Energy & Electricity — Key Concepts (AT1) Flashcards
(23 cards)
What is energy?
The ability to do work or cause a change.
What is the Law of Conservation of Energy?
Energy cannot be created or destroyed, only transformed or transferred.
What is energy efficiency?
A measure of how much useful energy is produced compared to the amount of energy put in.
What is the formula for energy efficiency?
Efficiency (%) = (Useful energy output ÷ Total energy input) × 100
What is wasted energy?
Energy that is not usefully transferred, often in the form of heat or sound.
What is an energy transformation?
The process of changing one form of energy into another.
What is a series circuit?
A circuit with only one pathway for the electric current to flow.
What is a parallel circuit?
A circuit with multiple pathways for current to flow through.
What happens to brightness of bulbs in a series circuit if more bulbs are added?
The brightness decreases because the voltage is shared.
What happens to brightness of bulbs in a parallel circuit if more bulbs are added?
The brightness stays the same because each bulb gets full voltage.
What is current?
The flow of electric charge, measured in amperes (A).
What is voltage?
The energy provided to each charge, measured in volts (V).
What is resistance?
The opposition to current, measured in ohms (Ω).
What is the formula for Ohm’s Law?
Voltage = Current × Resistance (V = I × R)
What is a resistor?
A component used to reduce or control current in a circuit.
How can energy efficiency be improved?
By reducing energy waste and increasing the amount of useful energy output.
What is renewable energy?
Energy that can be replaced naturally in a short amount of time.
What is non-renewable energy?
Energy that comes from sources that will eventually run out.
Give one benefit of renewable energy.
It is sustainable and does not run out quickly.
Give one challenge of using renewable energy.
It may depend on environmental conditions, which can vary.
What is an electric circuit?
A closed loop through which electric current can flow.
Why is a parallel circuit more reliable than a series circuit?
Because components can still work if one part of the circuit stops functioning.
What does a Sankey diagram represent?
It shows energy input, useful output, and wasted energy using arrows.
