Primary 5 · Science · Systems: Electrical Circuits
Systems: Electrical Circuits questions for Primary 5 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 series circuit
- Reading a parallel circuit
- Why houses use parallel
- Brightness in series
- Conductors and insulators
- Open and closed circuits
- Making a bulb brighter
- Naming the arrangement
- Naming a component
- Applying the ideas
| Material tested | Bulb lit? |
|---|---|
| copper wire | ✓ |
| plastic ruler | ✗ |
| steel key | ✓ |
| wooden lolly stick | ✗ |
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 circuit shown above, what happens if bulb A is removed from its holder?
Answer: Bulb B goes out as well.
There is only one path round this circuit. Taking out A breaks that path, so nothing flows and B goes out too.
In the circuit shown above, what happens if bulb A is removed from its holder?
Answer: Bulb B stays lit.
Each bulb is on its own branch, so there are two separate paths. Breaking one leaves the other complete, and B stays lit.
Why are the lights in a house wired in parallel rather than in series?
Answer: A, B and D only
Parallel wiring lets each lamp be switched separately, keeps the others alight when one fails, and gives every lamp the full voltage. It costs more wire, which is the price paid for all that.
One more identical bulb is added in series to the circuit shown above. What happens to the bulbs?
Answer: All the bulbs become dimmer.
In series the battery's push is shared between the bulbs. Three bulbs share it three ways, so every bulb is dimmer than before.
Based on the table above, which conclusion is correct?
Answer: The metals let electricity through and the non-metals did not.
Copper and steel are metals and both lit the bulb; plastic and wood are not metals and neither did. Metals are the conductors here.
Why does the bulb in the circuit shown above not light?
Answer: The open switch leaves a gap, so there is no complete path.
Electricity needs an unbroken loop. An open switch leaves a gap in that loop, so nothing flows and the bulb stays dark.
Which two of these would make a single bulb in a simple circuit shine more brightly?
Answer: A and B only
A second battery pushes harder, and thicker wires let the electricity through more easily. Adding bulbs in series does the opposite.
Look at how the two bulbs are arranged in the circuit above, each on its own branch. What is this arrangement called?
Answer: parallel
Bulbs on separate branches are connected in parallel.
This part is put into a circuit so that the path can be broken and completed again whenever you want. What is it called?
Answer: switch
The component used to break and complete a circuit is a switch.
A string of decorative lights goes completely dark when one bulb fails. What does this tell you about how they are wired?
Answer: They are wired in series, so one gap breaks the only path.
Only a series circuit behaves this way: there is a single path, so a break anywhere stops everything.