Circuits Year 4 - Circuits and switches science worksheet - Teachwire - Free Printable

Let’s go through each circuit one by one. We’ll check:

1. Is the circuit complete? (No gaps — all parts connected in a loop)
2. Is there a switch? If yes, is it closed (on) or open (off)?
3. Are the battery, bulb(s), and wires arranged so electricity can flow?

Remember:
- A bulb lights up only if the circuit is COMPLETE and the switch is CLOSED (if there is one).
- If the switch is OPEN, no current flows → bulb stays off.
- If any part of the loop is broken (like an open switch or missing wire), the bulb won’t light.

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Circuit 1 (Top Left)
- Has battery, two bulbs, NO switch.
- All parts are connected in a loop.
→ Prediction: YES, it will light up.
→ Did it light up? YES
→ Could you turn it on/off? NO — no switch!

Circuit 2 (Top Middle)
- Has battery, one bulb, ONE SWITCH — but the switch is OPEN (gap).
→ Prediction: NO, it won’t light up.
→ Did it light up? NO
→ Could you turn it on/off? YES — if you close the switch, it turns on; open it, it turns off.

Circuit 3 (Top Right)
- Has TWO batteries, two bulbs, NO switch.
- But look: the batteries are placed opposite each other (+ to + or - to -?) — actually, they’re connected correctly in series (positive of one to negative of next). Wait — let’s trace: from top battery’s +, goes to bulb, then to second battery’s -, then its + goes to other bulb, back to first battery’s -. Actually, this forms a complete loop with correct polarity.
→ Prediction: YES, both bulbs should light.
→ Did it light up? YES
→ Could you turn it on/off? NO — no switch.

Wait — correction: In Circuit 3, the two cells are connected end-to-end properly (series), forming a longer voltage source. The loop is complete. So yes, bulbs light. No switch → can’t turn off.

Circuit 4 (Middle Left)
- Battery, two bulbs, ONE SWITCH — switch is OPEN.
→ Prediction: NO, won’t light.
→ Did it light up? NO
→ Could you turn it on/off? YES — closing switch turns it on.

Circuit 5 (Middle Center)
- Battery, three bulbs, NO switch.
- All in a row — series circuit. Loop is complete.
→ Prediction: YES, all bulbs light (though dimmer than single bulb).
→ Did it light up? YES
→ Could you turn it on/off? NO — no switch.

Circuit 6 (Middle Right)
- Battery, two bulbs, TWO SWITCHES — both are OPEN.
→ Even if one switch were closed, the other is open → still broken circuit.
→ Prediction: NO, won’t light.
→ Did it light up? NO
→ Could you turn it on/off? YES — if you close BOTH switches, it turns on. Open either, it turns off.

Circuit 7 (Bottom Left)
- Battery, three bulbs, ONE SWITCH — switch is OPEN.
→ Prediction: NO, won’t light.
→ Did it light up? NO
→ Could you turn it on/off? YES — close switch to turn on.

Circuit 8 (Bottom Center)
- Battery, three bulbs, NO switch.
- Complete loop? Yes — all connected.
→ Prediction: YES, bulbs light.
→ Did it light up? YES
→ Could you turn it on/off? NO — no switch.

Circuit 9 (Bottom Right)
- Battery, three bulbs, ONE SWITCH — switch is OPEN.
→ Prediction: NO, won’t light.
→ Did it light up? NO
→ Could you turn it on/off? YES — close switch to turn on.

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Now let’s fill in the answers clearly for each box.

Final Answer:

Top Row:

Circuit 1:
Prediction: Yes
Did it light up? Yes
Could you turn the circuit on and off? No

Circuit 2:
Prediction: No
Did it light up? No
Could you turn the circuit on and off? Yes

Circuit 3:
Prediction: Yes
Did it light up? Yes
Could you turn the circuit on and off? No

Middle Row:

Circuit 4:
Prediction: No
Did it light up? No
Could you turn the circuit on and off? Yes

Circuit 5:
Prediction: Yes
Did it light up? Yes
Could you turn the circuit on and off? No

Circuit 6:
Prediction: No
Did it light up? No
Could you turn the circuit on and off? Yes

Bottom Row:

Circuit 7:
Prediction: No
Did it light up? No
Could you turn the circuit on and off? Yes

Circuit 8:
Prediction: Yes
Did it light up? Yes
Could you turn the circuit on and off? No

Circuit 9:
Prediction: No
Did it light up? No
Could you turn the circuit on and off? Yes