Compare conductors and insulators, series and parallel circuits, switches, fuses and circuit symbols. Review suitability for your learners before teaching.
Choose “Save as PDF” to keep a copy. Use your browser’s paper setting for A4 or Letter.
Worksheet StudioPractice pack · Ages 10-12
Conductors, insulators & circuits
Take your time. Show your thinking.
1. In a parallel circuit, how does the total current leaving the battery compare to the currents in the individual parallel branches: the total current equals the sum of the currents in the branches, or the total current is zero?
Cell (+) ── Switch ── (−) · Closed Series Loop
2. Why should you NEVER touch mains electrical switches, plugs or sockets with wet hands: tap water contains dissolved salts (ions) that conduct electricity and can cause a dangerous electric shock, or water freezes the switch?
Cell (+) ── Switch ── (−) · Closed Series Loop
3. In a simple SERIES circuit with two bulbs in a single loop, if one bulb’s filament breaks (blows), what happens to the other bulb: it goes out too because the single circuit loop is broken, or it stays lit?
Cell (+) ── Switch ── (−) · Closed Series Loop
4. In a simple SERIES circuit containing one battery and two bulbs, if you add a third identical bulb in the same single loop, what happens to the brightness of the bulbs: they become dimmer because the voltage is shared and total resistance increases, or they become three times brighter?
Cell (+) ── Switch ── (−) · Closed Series Loop
5. What component has a resistance that decreases when brighter light shines on it (used in automatic street lights): a light-dependent resistor (LDR) or a thermistor?
Cell (+) ── Switch ── (−) · Closed Series Loop
6. Which circuit instrument is connected IN PARALLEL across a component to measure the potential difference (voltage) in volts (V): a voltmeter or an ammeter?
Cell (+) ── Switch ── (−) · Closed Series Loop
7. If you add a second cell in series (pointing in the same direction, + to −) to a circuit with a single bulb, what happens to the bulb: it shines more brightly because the voltage pushing the current has doubled, or it goes out?
Cell (+) ── Switch ── (−) · Closed Series Loop
8. What circuit component allows current to flow in ONE direction only (and emits light when it is an LED): a diode (or light-emitting diode) or a fixed resistor?
Cell (+) ── Switch ── (−) · Closed Series Loop
9. What component has a resistance that changes significantly with temperature (used in digital thermometers and thermostats): a thermistor or a loudspeaker?
Cell (+) ── Switch ── (−) · Closed Series Loop
10. Why are the lights and sockets in a home wired in PARALLEL rather than in series: each light is on its own branch so it receives full voltage and can be switched on or off independently without turning off the others, or parallel uses no wire?
Cell (+) ── Switch ── (−) · Closed Series Loop
11. For an electric current to flow and light up a bulb, what kind of path must the circuit form from one terminal of the battery to the other: a complete (closed) loop with no gaps, or a broken (open) loop?
Cell (+) ── Switch ── (−) · Closed Series Loop
12. What safety device inside a plug or fusebox contains a thin wire designed to melt and break the circuit if the current becomes dangerously high: a fuse or a motor?
Cell (+) ── Switch ── (−) · Closed Series Loop
12 questions · Seed 45 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 10-12
Conductors, insulators & circuits
Answers and reasoning. Review before teaching.
1. In a parallel circuit, how does the total current leaving the battery compare to the currents in the individual parallel branches: the total current equals the sum of the currents in the branches, or the total current is zero?
The total current equals the sum of the currents in the branches
By Kirchhoff’s current law (conservation of charge), current splits at a junction and recombines on return.
2. Why should you NEVER touch mains electrical switches, plugs or sockets with wet hands: tap water contains dissolved salts (ions) that conduct electricity and can cause a dangerous electric shock, or water freezes the switch?
Tap water contains dissolved salts (ions) that conduct electricity and can cause a dangerous electric shock
Impure water is an electrical conductor and lowers the electrical resistance of skin.
3. In a simple SERIES circuit with two bulbs in a single loop, if one bulb’s filament breaks (blows), what happens to the other bulb: it goes out too because the single circuit loop is broken, or it stays lit?
It goes out too because the single circuit loop is broken
A break anywhere in a series loop stops current throughout the entire loop.
4. In a simple SERIES circuit containing one battery and two bulbs, if you add a third identical bulb in the same single loop, what happens to the brightness of the bulbs: they become dimmer because the voltage is shared and total resistance increases, or they become three times brighter?
They become dimmer because the voltage is shared and total resistance increases
In a series loop, adding more bulbs increases resistance and splits the battery voltage across more components.
5. What component has a resistance that decreases when brighter light shines on it (used in automatic street lights): a light-dependent resistor (LDR) or a thermistor?
Light-dependent resistor (LDR)
In bright light an LDR’s resistance falls; in darkness its resistance rises.
6. Which circuit instrument is connected IN PARALLEL across a component to measure the potential difference (voltage) in volts (V): a voltmeter or an ammeter?
Voltmeter
A voltmeter has very high resistance and is connected across (in parallel with) a component.
7. If you add a second cell in series (pointing in the same direction, + to −) to a circuit with a single bulb, what happens to the bulb: it shines more brightly because the voltage pushing the current has doubled, or it goes out?
It shines more brightly because the voltage pushing the current has doubled
Two 1.5 V cells connected correctly in series supply 3.0 V, increasing the current through the bulb.
8. What circuit component allows current to flow in ONE direction only (and emits light when it is an LED): a diode (or light-emitting diode) or a fixed resistor?
Diode (or light-emitting diode)
A diode has low resistance in the forward direction and very high resistance in reverse.
9. What component has a resistance that changes significantly with temperature (used in digital thermometers and thermostats): a thermistor or a loudspeaker?
Thermistor
A thermistor is a temperature-sensitive resistor.
10. Why are the lights and sockets in a home wired in PARALLEL rather than in series: each light is on its own branch so it receives full voltage and can be switched on or off independently without turning off the others, or parallel uses no wire?
Each light is on its own branch so it receives full voltage and can be switched on or off independently without turning off the others
In a parallel circuit, if one lamp fails or is switched off, current still flows through the other branches.
11. For an electric current to flow and light up a bulb, what kind of path must the circuit form from one terminal of the battery to the other: a complete (closed) loop with no gaps, or a broken (open) loop?
A complete (closed) loop with no gaps
Current only flows around a continuous, closed conducting pathway.
12. What safety device inside a plug or fusebox contains a thin wire designed to melt and break the circuit if the current becomes dangerously high: a fuse or a motor?
Fuse
If a fault causes excessive current, the fuse wire melts, cutting off the electricity to prevent overheating and fire.
12 questions · Seed 45 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12
Conductors, insulators & circuits
Take your time. Show your thinking.
1. In a parallel circuit, how does the total current leaving the battery compare to the currents in the individual parallel branches: the total current equals the sum of the currents in the branches, or the total current is zero?
Cell (+) ── Switch ── (−) · Closed Series Loop
2. Why should you NEVER touch mains electrical switches, plugs or sockets with wet hands: tap water contains dissolved salts (ions) that conduct electricity and can cause a dangerous electric shock, or water freezes the switch?
Cell (+) ── Switch ── (−) · Closed Series Loop
3. In a simple SERIES circuit with two bulbs in a single loop, if one bulb’s filament breaks (blows), what happens to the other bulb: it goes out too because the single circuit loop is broken, or it stays lit?
Cell (+) ── Switch ── (−) · Closed Series Loop
4. In a simple SERIES circuit containing one battery and two bulbs, if you add a third identical bulb in the same single loop, what happens to the brightness of the bulbs: they become dimmer because the voltage is shared and total resistance increases, or they become three times brighter?
Cell (+) ── Switch ── (−) · Closed Series Loop
5. What component has a resistance that decreases when brighter light shines on it (used in automatic street lights): a light-dependent resistor (LDR) or a thermistor?
Cell (+) ── Switch ── (−) · Closed Series Loop
6. Which circuit instrument is connected IN PARALLEL across a component to measure the potential difference (voltage) in volts (V): a voltmeter or an ammeter?
Cell (+) ── Switch ── (−) · Closed Series Loop
7. If you add a second cell in series (pointing in the same direction, + to −) to a circuit with a single bulb, what happens to the bulb: it shines more brightly because the voltage pushing the current has doubled, or it goes out?
Cell (+) ── Switch ── (−) · Closed Series Loop
8. What circuit component allows current to flow in ONE direction only (and emits light when it is an LED): a diode (or light-emitting diode) or a fixed resistor?
Cell (+) ── Switch ── (−) · Closed Series Loop
9. What component has a resistance that changes significantly with temperature (used in digital thermometers and thermostats): a thermistor or a loudspeaker?
Cell (+) ── Switch ── (−) · Closed Series Loop
10. Why are the lights and sockets in a home wired in PARALLEL rather than in series: each light is on its own branch so it receives full voltage and can be switched on or off independently without turning off the others, or parallel uses no wire?
Cell (+) ── Switch ── (−) · Closed Series Loop
11. For an electric current to flow and light up a bulb, what kind of path must the circuit form from one terminal of the battery to the other: a complete (closed) loop with no gaps, or a broken (open) loop?
Cell (+) ── Switch ── (−) · Closed Series Loop
12. What safety device inside a plug or fusebox contains a thin wire designed to melt and break the circuit if the current becomes dangerously high: a fuse or a motor?
Cell (+) ── Switch ── (−) · Closed Series Loop
12 questions · Seed 45 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12
Conductors, insulators & circuits
Answers and reasoning. Review before teaching.
1. In a parallel circuit, how does the total current leaving the battery compare to the currents in the individual parallel branches: the total current equals the sum of the currents in the branches, or the total current is zero?
The total current equals the sum of the currents in the branches
By Kirchhoff’s current law (conservation of charge), current splits at a junction and recombines on return.
2. Why should you NEVER touch mains electrical switches, plugs or sockets with wet hands: tap water contains dissolved salts (ions) that conduct electricity and can cause a dangerous electric shock, or water freezes the switch?
Tap water contains dissolved salts (ions) that conduct electricity and can cause a dangerous electric shock
Impure water is an electrical conductor and lowers the electrical resistance of skin.
3. In a simple SERIES circuit with two bulbs in a single loop, if one bulb’s filament breaks (blows), what happens to the other bulb: it goes out too because the single circuit loop is broken, or it stays lit?
It goes out too because the single circuit loop is broken
A break anywhere in a series loop stops current throughout the entire loop.
4. In a simple SERIES circuit containing one battery and two bulbs, if you add a third identical bulb in the same single loop, what happens to the brightness of the bulbs: they become dimmer because the voltage is shared and total resistance increases, or they become three times brighter?
They become dimmer because the voltage is shared and total resistance increases
In a series loop, adding more bulbs increases resistance and splits the battery voltage across more components.
5. What component has a resistance that decreases when brighter light shines on it (used in automatic street lights): a light-dependent resistor (LDR) or a thermistor?
Light-dependent resistor (LDR)
In bright light an LDR’s resistance falls; in darkness its resistance rises.
6. Which circuit instrument is connected IN PARALLEL across a component to measure the potential difference (voltage) in volts (V): a voltmeter or an ammeter?
Voltmeter
A voltmeter has very high resistance and is connected across (in parallel with) a component.
7. If you add a second cell in series (pointing in the same direction, + to −) to a circuit with a single bulb, what happens to the bulb: it shines more brightly because the voltage pushing the current has doubled, or it goes out?
It shines more brightly because the voltage pushing the current has doubled
Two 1.5 V cells connected correctly in series supply 3.0 V, increasing the current through the bulb.
8. What circuit component allows current to flow in ONE direction only (and emits light when it is an LED): a diode (or light-emitting diode) or a fixed resistor?
Diode (or light-emitting diode)
A diode has low resistance in the forward direction and very high resistance in reverse.
9. What component has a resistance that changes significantly with temperature (used in digital thermometers and thermostats): a thermistor or a loudspeaker?
Thermistor
A thermistor is a temperature-sensitive resistor.
10. Why are the lights and sockets in a home wired in PARALLEL rather than in series: each light is on its own branch so it receives full voltage and can be switched on or off independently without turning off the others, or parallel uses no wire?
Each light is on its own branch so it receives full voltage and can be switched on or off independently without turning off the others
In a parallel circuit, if one lamp fails or is switched off, current still flows through the other branches.
11. For an electric current to flow and light up a bulb, what kind of path must the circuit form from one terminal of the battery to the other: a complete (closed) loop with no gaps, or a broken (open) loop?
A complete (closed) loop with no gaps
Current only flows around a continuous, closed conducting pathway.
12. What safety device inside a plug or fusebox contains a thin wire designed to melt and break the circuit if the current becomes dangerously high: a fuse or a motor?
Fuse
If a fault causes excessive current, the fuse wire melts, cutting off the electricity to prevent overheating and fire.
12 questions · Seed 45 · Age guidance, not curriculum certification