Section 1: Prior Knowledge
1. Name one device you use daily that works with electricity.
Answer:
· Electric fan
· LED bulb
2. When you switch OFF a device, what do you think happens to the flow of electricity inside it?
Answer:
When the switch is turned OFF, the electric circuit becomes open, so the flow of electric current stops.
3. Have you ever seen a bulb glow when connected to a battery? What do you think is needed to make the bulb glow?
Answer:
Yes.
A bulb glows only when:
· a battery (cell) is connected,
· connecting wires are used,
· the bulb is connected correctly,
· the circuit is closed (complete).
Section 2: Activity Log
1. Aim
Answer:
To identify electrical symbols and construct a simple electric circuit using a battery, bulb, wires, and a switch.
2. Materials
Answer:
· Electric cell (battery)
· Bulb
· Bulb holder
· Connecting wires
· Switch (paper clip/safety pin switch)
· Base board
3. Hypothesis
✔ Bulb glows only when the electric circuit is complete.
Correct
✔ Adding a switch in a circuit helps control the flow of electricity by opening or closing the circuit.
Correct
Other hypothesis
The bulb will glow only when all electrical components are connected properly and the battery is working.
4. Procedure Part A
Identify the symbols.
Symbol | Component |
a | Electric Cell |
b | Electric Bulb (Lamp) |
c | Open Switch |
d | Connecting Wire |
e | Battery |
5. Procedure Part B
What did you observe when you connected the circuit properly?
Answer:
The bulb glowed because the circuit was complete and current flowed from the battery through the bulb.
6. Procedure Part C
What did you observe when you used the switch in your circuit?
Answer:
· When the switch was closed, the bulb glowed.
· When the switch was opened, the bulb went off.
· The switch controlled the flow of electric current.
Draw the circuit with switch.
Teacher's Expected Diagram
Section 3: Analyse, Apply and Reflect
1. How did the metal pin act as a switch in your circuit?
Answer
The metal pin completed the circuit when it touched both ends of the wire. This allowed electric current to flow and the bulb glowed. When the pin was lifted, the circuit became open and the bulb went off.
2. A battery-operated toy stops working after some time, even though the switch is ON. What should be checked first and why?
Answer
First, check whether the battery is discharged or connected properly.
A weak or dead battery cannot supply enough electric current to operate the toy.
3. Did your chosen hypothesis match your observation? Mention one observation.
Answer
Yes.
Observation:
The bulb glowed only when the circuit was complete and the switch was closed.
Section 4: Competency-Based Assessment
1. What happens in a closed circuit?
✅ Answer:
Electricity flows.
2. Which of the following is necessary for electric current to flow?
✅ Answer:
A complete (closed) path
3. Assertion–Reason
Assertion:
Adding a switch in a circuit does not affect whether the bulb glows.
Reason:
A switch controls the flow of electric current by opening or closing the circuit.
Correct Answer
✅ A is incorrect, but R is correct.
4. When the switch is turned ON, what is the order in which the bulbs will glow?
Answer
✅ A, B and C glow at the same time.
Reason:
Current flows throughout the closed circuit almost instantly.
5. If a bulb glows only sometimes when you move a wire, what does this tell you about the circuit?
Answer
There is a loose connection or improper contact in the circuit. The wire should be connected firmly.
6. A student notices that a lamp keeps glowing whether the switch is ON or OFF. What could be one possible reason?
Answer
The switch has been bypassed or connected incorrectly, so the current flows continuously.
7. Analyse the circuit. Why is the bulb not glowing? What change should be made?
Answer
Reason:
The switch is open, so the circuit is incomplete.
Correction:
Close the switch to complete the circuit.
8. Explain the difference between an open circuit and a closed circuit.
Open Circuit | Closed Circuit |
Path is broken. | Path is complete. |
Current does not flow. | Current flows. |
Bulb does not glow. | Bulb glows. |
Switch is OFF/Open. | Switch is ON/Closed. |
9. Three batteries—one good, one weak, and one empty—are given. How would you identify each?
Answer
Connect each battery to the same bulb using the same wires.
Observation:
· Good battery → Bulb glows brightly.
· Weak battery → Bulb glows dimly.
· Empty battery → Bulb does not glow.
10. You are making a small stage for a play. One bulb should glow during a happy scene and another during a sad scene. How would you arrange the circuit?
Answer
Use:
· One battery
· Two bulbs
· Two separate switches
· Connect each bulb in a separate branch with its own switch.
This allows each bulb to be switched on independently.
Example:
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