Let's analyze each of the four electrical circuits shown in the image and determine whether the bulb will light, along with an explanation for each.
---
Circuit 1:
-
Components: Battery, switch (closed), bulb, wires.
-
Switch state: The switch is
closed (connected).
-
Path: There is a complete path from the battery through the switch and bulb back to the battery.
✔ Will the bulb light? Yes.
Why? The circuit is complete. The switch is closed, allowing current to flow from the battery through the bulb, causing it to light up.
---
Circuit 2:
-
Components: Battery, switch, bulb.
-
Switch state: The switch is
open (broken).
-
Path: The circuit is broken at the switch.
✘ Will the bulb light? No.
Why? The switch is open, so there is no complete path for the electric current to flow. Without current, the bulb will not light.
---
Circuit 3:
-
Components: Battery, but
no bulb or other component.
-
Path: Wires connect directly from one terminal of the battery to the other, forming a
short circuit.
✘ Will the bulb light? No.
Why? There is no bulb in the circuit. Even though the circuit is complete, there is no load (like a bulb) to use the electricity. Also, this is a short circuit — current flows directly from the battery’s positive to negative terminal without passing through any useful component. This can be dangerous and may damage the battery.
---
Circuit 4:
-
Components: Bulb, but
no battery.
-
Path: Wires connect the bulb, but there is
no power source.
✘ Will the bulb light? No.
Why? There is no battery or power source to provide electrical energy. Without a voltage source, no current will flow, so the bulb cannot light.
---
✔ Summary Table:
| Circuit | Will the bulb light? | Why / Why not? |
|--------|----------------------|----------------|
| 1 | Yes | Complete circuit with closed switch and bulb. Current flows. |
| 2 | No | Switch is open → broken circuit → no current. |
| 3 | No | No bulb present; short circuit – no load. |
| 4 | No | No battery → no power source → no current. |
---
This worksheet helps students understand the basics of
complete circuits, the role of a
switch, and the necessity of both a
power source (battery) and a
load (bulb) for a circuit to function properly.
Parent Tip: Review the logic above to help your child master the concept of electric circuits worksheets with answers pdf.
