Energy Types
Energy Transformations
Energy Efficiency
Electrical Energy
Electrical Energy Conversions
100
What is the energy of a moving object called?
Kinetic energy
100
What energy transformation happens in a torch (flashlight)?
Chemical energy (battery) → Electrical energy → Light energy
100
What does “energy efficiency” mean?
Using less energy to perform the same task; less energy wasted as heat, sound, etc.
100
What makes a circuit complete?
A closed loop with a power source and load (e.g., bulb); current can flow.
100
What energy transformation occurs in a toaster?
Electrical energy → Heat energy
200
What type of energy is stored in a battery?
Chemical energy
200
What is the energy change when food is eaten by a person?
Chemical energy (food) → Kinetic energy (movement) and heat energy
200
Why are LED bulbs considered more energy efficient than traditional bulbs?
They convert more electrical energy into light and waste less as heat.
200
What is a series circuit?
All components are connected one after another in a single loop.
200
What does a solar panel convert light energy into?
Electrical energy
300
What kind of energy does a stretched rubber band have?
Elastic potential energy
300
Describe the energy transformations when riding a bicycle uphill.
Chemical energy (muscles) → Kinetic energy (pedals/wheels) → Gravitational potential energy (bike at top)
300
Give two ways to improve the energy efficiency of a home.
Insulation, using energy-efficient appliances, turning off lights when not needed
300
What happens if one bulb breaks in a series circuit?
The circuit is broken; all bulbs go out.
300
Describe the energy conversions in a radio.
Electrical energy → Sound energy (and a little heat)
400
Name three different types of energy found in everyday life.
Kinetic, potential, chemical (others: thermal, light, sound, electrical)
400
How does energy change when a television is turned on?
Electrical energy → Light energy (screen) + Sound energy
400
Why do machines lose energy and not turn all input energy into useful output?
Some energy is always lost as heat, sound, or friction.
400
Explain how a parallel circuit works and why it is used in houses.
Components are in separate branches; if one bulb goes out, others stay on; so, faults don’t affect all devices.
400
Explain the energy conversions in a hydroelectric power station.
Gravitational potential (dams) → Kinetic energy (falling water) → Electrical energy (turbines)
500
Explain the difference between potential energy and kinetic energy, with examples.
Potential energy is stored due to position or condition (e.g., a stretched bow), kinetic energy is energy of movement (e.g., a flying arrow).
500
Explain the sequence of energy transformations in a bottle rocket experiment.
Chemical energy (reaction) → Gas pressure (potential) → Kinetic energy (motion) → Sound and heat energy
500
Describe how energy efficiency can affect environmental sustainability.
Higher efficiency means less energy used, reducing resource consumption and pollution (lower environmental impact).
500
Draw and label a parallel circuit with three bulbs and explain how each bulb works if one breaks.
500
Discuss how electrical energy can be converted into many other types of energy, giving at least three examples.
Electrical energy can become light (lamp), heat (heater), sound (speaker), motion (fan or motor), chemical (charging battery)