Let's solve the science worksheet step by step and explain each answer clearly.
---
Q1: Answer the following questions
####
a- What happens to the bulb if we turn the switch on?
Answer:
When we turn the switch on, the circuit becomes
closed, allowing electricity to flow from the battery through the wires to the bulb. This causes the bulb to
light up.
Explanation:
In a closed circuit, there is a complete path for electric current to travel. The switch connects the two ends of the circuit, enabling electrons to move and power the bulb. In contrast, in an open circuit (switch off), the path is broken, so no current flows.
---
####
b- In which circuit does electricity cannot flow? Explain why?
Answer:
Electricity
cannot flow in the
open circuit.
Explanation:
In the open circuit, the switch is in the "off" position, which breaks the path of the circuit. Because the circuit is not complete, electrons cannot flow from the battery to the bulb and back. Without a continuous loop, electric current stops — so the bulb remains off.
>
✔ Key Concept: For electricity to flow, a circuit must be
closed (complete).
---
Q2: Why do appliances have a plastic-covered plug?
Answer:
Appliances have a plastic-covered plug because
plastic is an insulator — it does not conduct electricity. This helps prevent electric shocks and keeps users safe.
Explanation:
The metal pins inside the plug carry electricity, but the plastic casing around them prevents accidental contact with live parts. If someone touches the plug, the plastic stops the current from passing through their body. This is an important safety feature in electrical devices.
>
✔ Key Concept: Insulators like plastic protect against electric shock by blocking the flow of electricity.
---
✔ Final Summary:
| Question | Answer |
|--------|--------|
| Q1a | The bulb lights up because the circuit becomes complete when the switch is turned on. |
| Q1b | Electricity cannot flow in the
open circuit because the switch is off, breaking the path. |
| Q2 | Plastic covers the plug to act as an insulator and prevent electric shocks. |
---
This worksheet teaches basic concepts of
electric circuits and
electrical safety — essential topics in Stage 4 science!
Parent Tip: Review the logic above to help your child master the concept of electricity worksheet 4th grade.
