Primary 6 · Science · Energy: Forms & Conversion
Energy: Forms & Conversion questions for Primary 6 Science
10 questions to work through online, 2 of them written out the way the paper asks. Answer and you get the working straight away, then a score at the end. No sign-up, and you can retake it as often as you like.
- Reading a conversion chain
- Naming a conversion
- Identifying stored energy
- Following a longer chain
- The energy always lost
- Comparing efficiency
- Sources of energy
- Naming a form
- Applying the ideas
| Bulb | Electrical energy used (units) | Light energy given out (units) |
|---|---|---|
| P | 100 | 5 |
| Q | 100 | 22 |
| R | 100 | 40 |
Answers and explanations for all 10 questions
Every answer with the reasoning behind it. Worth reading after you have tried the set — or on its own, if you are a parent marking it.
In the diagram above, which form of energy is stored before the torch is switched on?
Answer: W
W is the chemical energy stored in the battery. Switching on converts it to electrical energy and then to light.
A hair dryer is switched on. Which conversion best describes what happens?
Answer: electrical energy to heat energy and kinetic energy
The mains supplies electrical energy. The element turns it into heat and the fan turns it into the kinetic energy of moving air.
Which of these store energy before it is used?
Answer: A, B, C and D
All four are stores. A stretched band and a raised book hold energy by position or shape; a battery and food hold it chemically until it is released.
A child eats breakfast, then cycles to school. Which chain describes the energy conversion?
Answer: chemical energy in food to kinetic energy of the bicycle
The food carries chemical energy. The child's muscles release it and turn it into the movement of the bicycle, with heat given off along the way.
A light bulb becomes warm while it is on. What does this show?
Answer: Not all the electrical energy is converted into light; some becomes heat.
The electrical energy going in has to go somewhere. What does not leave as light leaves as heat, which is why a bulb is warm to the touch.
Based on the table above, which bulb wastes the most energy as heat?
Answer: P
Each bulb takes 100 units. P turns only 5 into light, so 95 units leave as heat — more waste than either of the others.
Which two of these are renewable sources of energy?
Answer: A and B only
Wind and sunlight arrive continuously and are not used up. Coal and petrol are fossil fuels: once burnt, they are gone on any human timescale.
A moving car, a falling ball and blowing wind all have this form of energy. What is it called? ______ energy.
Answer: kinetic
The energy of a moving object is kinetic energy.
Food, a battery and a lump of coal all store energy in this form until it is released. What is it called? ______ energy.
Answer: chemical
Energy stored in food, batteries and fuel is chemical energy.
A ball is dropped and bounces back to a lower height each time. Where has the missing energy gone?
Answer: It has become heat and sound as the ball hits the floor.
Each bounce converts some of the ball's energy into heat in the ball and floor, and into the sound you hear. Less is left to lift the ball, so it rises lower.