Series and parallel circuit 2 worksheet - Free Printable

Let's go through each circuit one by one and determine whether the bulbs are glowing ("on") or not ("off"). We'll use basic principles of electric circuits:

- A bulb glows only if there is a complete path (closed circuit) from the positive terminal of the battery to the negative terminal, passing through the bulb.
- If a switch is open, it breaks the circuit — no current flows.
- In series circuits, all components must be connected in a single loop; if one component fails or a switch opens, the whole circuit stops.
- In parallel circuits, each branch can operate independently.

We’ll analyze each diagram systematically.

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1. Top Row (Right Side)

#### Circuit 1: Two bulbs in parallel, with a switch in series with the battery
- The switch is open.
- Since the switch is open, no current flows anywhere in the circuit.
- Both bulbs are off.

✔ Answer: Both bulbs → off

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#### Circuit 2: Three bulbs in parallel, one switch in series with the battery
- The switch is open.
- Open switch → no current → all bulbs off.

✔ Answer: All three bulbs → off

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#### Circuit 3: Two bulbs in series, one switch in series with the battery
- Switch is closed.
- Complete circuit → current flows through both bulbs.
- Both bulbs are on.

✔ Answer: Both bulbs → on

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#### Circuit 4: Two bulbs in series, but one has a switch in parallel with it
- This is tricky: the switch is in parallel with the bottom bulb.
- When the switch is closed, it creates a short circuit across the bottom bulb.
- Current will flow through the switch (low resistance), bypassing the bottom bulb.
- So:
- Top bulb: on (current flows)
- Bottom bulb: off (bypassed)

✔ Answer: Top bulb → on, Bottom bulb → off

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2. Middle Row

#### Circuit 5: Three bulbs in series, switch open
- Switch is open → no complete path → all bulbs off

✔ Answer: All bulbs → off

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#### Circuit 6: Bulbs A, B, C
- Bulb A is in series with the battery.
- Bulbs B and C are in parallel with each other, and this combination is in parallel with bulb A?
Wait — let’s redraw mentally:
- Battery → bulb A → then splits into two paths: one with bulb B, one with bulb C.
- Then they recombine and return to battery.
- So bulb A is in series with the parallel combination of B and C.
- But wait — is there a switch? No, just labeled S between B and C.

Actually, looking closely: There's a switch S in series with bulb B.

So:
- Bulb A: always in the main path → gets current
- Bulb B: only if switch S is closed
- Bulb C: directly connected, no switch → always on?

But the switch S is in series with B, so:
- If switch S is closed, then B lights up
- If open, B is off

But we don't know the state of S. Wait — in the diagram, S is shown as open (gap in line).

So:
- Bulb A: in main path → on
- Bulb B: switch open → off
- Bulb C: in parallel with B, but no switch → on

✔ Answer:
- A → on
- B → off
- C → on

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#### Circuit 7: Three bulbs in parallel, one switch in series with the battery
- Switch is open → no current → all bulbs off

✔ Answer: All bulbs → off

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3. Bottom Row

#### Circuit 8: Two bulbs in parallel, switch in series with battery
- Switch is open → no current → both bulbs off

✔ Answer: Both bulbs → off

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#### Circuit 9: Three bulbs in parallel, each with its own switch
- Only top bulb has a switch that is closed
- Middle bulb: switch open → off
- Bottom bulb: switch closed → on
- Top bulb: switch closed → on

Wait — actually, looking at the diagram:
- Each branch has a bulb and a switch in series.
- Top: switch closed → bulb on
- Middle: switch open → bulb off
- Bottom: switch closed → bulb on

✔ Answer:
- Top bulb → on
- Middle bulb → off
- Bottom bulb → on

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#### Circuit 10: Three bulbs in series, one switch in series with the battery
- Switch is closed → complete circuit → all bulbs on

✔ Answer: All bulbs → on

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Now, let’s summarize all answers clearly:

We label them left to right, top to bottom.

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Final Answers:

1. Top-right (first row, first column):
- Two bulbs in parallel, switch open → both off

2. Top-middle:
- Two bulbs in parallel, switch open → both off

3. Top-left:
- Two bulbs in series, switch closed → both on

4. Middle-left:
- Three bulbs in series, switch open → all off

5. Middle-center:
- Bulbs A, B, C:
- A: on
- B: off (switch open)
- C: on

6. Middle-right:
- Three bulbs in parallel, switch open → all off

7. Bottom-left:
- Two bulbs in parallel, switch open → both off

8. Bottom-center:
- Three bulbs in parallel, each with switch:
- Top: on
- Middle: off
- Bottom: on

9. Bottom-right:
- Three bulbs in series, switch closed → all on

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✔ Final Answer Table:

| Circuit | Bulb Status |
|--------|-------------|
| 1 (Top-right) | Both bulbs → off |
| 2 (Top-middle) | Both bulbs → off |
| 3 (Top-left) | Both bulbs → on |
| 4 (Middle-left) | All bulbs → off |
| 5 (Middle-center) | A: on, B: off, C: on |
| 6 (Middle-right) | All bulbs → off |
| 7 (Bottom-left) | Both bulbs → off |
| 8 (Bottom-center) | Top: on, Middle: off, Bottom: on |
| 9 (Bottom-right) | All bulbs → on |

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> 🔍 Note: In the example box, it shows:
> - One bulb: on
> - One bulb: off (because switch is open)
> - One bulb: on
>
> That matches our logic.

Let me know if you'd like a visual version or explanation for any specific circuit!