Types of Energy/Transformations
Name the type of energy stored in food.
Chemical Energy
What does an energy-efficient appliance do?
Uses less energy to do the same job
In a series circuit, how many paths does the current have?
One
State Ohm’s Law.
V = IR
Name one of the 3 main renewable energy sources in Australia.
solar, wind, hydro
What energy transformation occurs in a toaster?
Electrical → thermal/heat energy
Why are LED lights more energy efficient than incandescent bulbs?
Less energy lost as heat
Which circuit type keeps working if one bulb blows: series or parallel?
Parallel
What is the unit for measuring resistance in something.
Ohms
Which renewable energy source uses moving air to generate electricity?
Wind energy
A rollercoaster reaches the top of a hill. What two main energy changes occur as it goes down?
Gravitational potential → kinetic energy
Explain why insulation improves energy efficiency in homes.
Reduces heat transfer/loss
What happens to total resistance when more resistors are added in series?
Resistance increases
A circuit has a voltage of 12 V and a resistance of 4 Ω. What is the current?
3 A
Explain one challenge of relying on solar or wind energy.
e.g Weather dependent/intermittent or other suitable answers
During photosynthesis, what energy transformation takes place?
Light energy → chemical energy
A machine is 70% efficient. What happens to the other 30% of the energy?
Lost to surroundings, usually as heat or sound
Why is current the same everywhere in a series circuit?
Only one path for charge flow
A resistor connected to 24 V draws 0.5 A. Calculate the resistance.
48 Ω
Some people argue that hydroelectric power is not completely environmentally friendly. Explain one reason why.
Dams can flood habitats, disrupt ecosystems, or affect fish migration
Explain why no energy transformation is ever 100% efficient.
Some energy is always transferred to unwanted forms like heat or sound due to friction/resistance.
A power station outputs 800 J of useful energy from 1000 J input. Calculate efficiency.
80%
Compare current and voltage in series vs parallel circuits.
Series: same current, shared voltage. Parallel: same voltage, split current.
Two resistors of 12 Ω and 18 Ω are connected in series to a 60 V battery. Calculate the total current flowing through the circuit.
2 A
State one advantage of nuclear power AND one disadvantage
advantage — low emissions;
disadvantage — radioactive waste, cost, or long build time