Circuit Testing worksheet: Determine if bulbs will light in various circuit diagrams.

Let's analyze each circuit in the worksheet to determine whether the bulb(s) will light. For a bulb to light, there must be a complete closed circuit with a power source (battery), a conductive path, and no breaks or open switches.

We'll go through each row and column one by one:

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Row 1:

Circuit 1 (Left):
- Battery and one bulb connected in a loop.
- ✔ Complete circuit.
- Answer: Yes

Circuit 2 (Right):
- Two batteries and two bulbs — but they are arranged in a way that creates two separate loops? Wait, actually, it looks like a series circuit: battery → bulb → battery → bulb → back to battery.
- But wait — this is problematic: two batteries are in opposite directions (one positive up, one positive down). This creates a conflict in polarity.
- However, if we assume both batteries are oriented the same way (but drawn poorly), then current can flow.
- But looking closely: The second battery is drawn with positive on bottom, which may oppose the first battery.
- In real terms, if batteries are connected in series in opposite directions, their voltages cancel out.
- So unless the batteries are aiding each other, the net voltage is zero.
- But here, since both are shown with same orientation (top +, bottom -), it's likely just a drawing issue.
- Actually, the second battery is flipped: top is negative, bottom is positive — so it’s reversed.
- So the two batteries are opposing each other → net voltage = 0.
- Therefore, no current flows.
- Answer: No

Wait — let's recheck:
- First battery: top (+), bottom (-)
- Second battery: top (-), bottom (+) → so it's reverse
- So they are connected back-to-back, opposing each other.
- Net voltage = 0 → no current.
- Answer: No

✔ Final: No

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Row 2:

Circuit 3 (Left):
- Just a bulb with no battery.
- No power source → no current.
- Answer: No

Circuit 4 (Right):
- Battery and bulb, but a switch is open (gap).
- Open switch → break in circuit → no current.
- Answer: No

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Row 3:

Circuit 5 (Left):
- Three batteries in series (all aligned: + to -), and one bulb.
- Full circuit → current flows.
- Answer: Yes

Circuit 6 (Right):
- Two batteries connected in parallel? But look: both positive terminals connected together, both negative together?
- But no bulb in the circuit!
- Only two batteries connected directly — no load.
- This is a short circuit? But even so, no bulb is present.
- The question is: "Will the bulbs light?" — but there is no bulb in this circuit.
- So no bulb → cannot light.
- Answer: No

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Row 4:

Circuit 7 (Left):
- Battery, switch, bulb — but switch is open.
- Open circuit → no current.
- Answer: No

Circuit 8 (Right):
- Two batteries in series, bulb in between.
- But the connections: battery → bulb → battery → back to first battery?
- Let's trace: from first battery (+) → bulb → second battery (+)? That doesn't make sense.
- Actually, it seems like the bulb is in parallel with the batteries?
- Or perhaps it's a loop: battery A (+) → bulb → battery B (+)? No, that’s not possible.
- Wait: The diagram shows:
- Top: wire connects battery A (+) to bulb
- Bulb to battery B (+)?
- But battery B has its own negative terminal.
- This appears to be a short circuit: batteries connected in series, but the bulb is across them? Not properly connected.
- Actually, it looks like both batteries are connected in parallel with the bulb.
- But the wires show:
- Left side: battery A and battery B have their negatives connected.
- Right side: bulb connected between positive of A and positive of B?
- But that would mean bulb is across both positives → not correct.
- Alternatively, it might be a parallel connection of batteries with the bulb in series.
- But the wiring is ambiguous.

Wait — better interpretation:
- Two batteries in series: A+ to B-, and B+ to bulb, bulb to A-? No.
- Actually, the diagram shows:
- One battery on left, one on right, bulb in middle.
- Wires connect: battery A (+) → bulb → battery B (+)? No, that can't happen.
- Looking at standard symbols:
- Battery: long line = positive, short line = negative.
- Left battery: top (+), bottom (-)
- Right battery: top (-), bottom (+) → so reversed?
- Then bulb in center: connected from left battery's top to right battery's bottom?
- So: left battery (+) → bulb → right battery (-) → but right battery's negative is on top, positive on bottom.
- Then how does it close?

Actually, the circuit seems to be:
- Left battery: + to bulb
- Bulb to right battery: -
- Then right battery: + to left battery: -?
- So: left battery (+) → bulb → right battery (-) → right battery (+) → ??? No, that's not closing.

Wait — perhaps the wires are connecting:
- Left battery: top (+) → bulb → right battery: top (-) → then right battery bottom (+) → left battery bottom (-) → back to start?

But that would require the right battery to be reversed.

This is confusing.

Alternatively, it's possible that both batteries are in parallel with the bulb.

But the best interpretation is:
- Two batteries in series, with the bulb in series with them.
- But the direction of the second battery is reversed — so they oppose each other.

So net voltage = 0 → no current → bulb won’t light.

Answer: No

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Row 5:

Circuit 9 (Left):
- Two bulbs in parallel, but no battery.
- No power source → no current.
- Answer: No

Circuit 10 (Right):
- Battery, one bulb, and two more bulbs in series below.
- So: battery → bulb → bulb → bulb → back to battery?
- All in series.
- Closed loop → current flows → all bulbs should light.
- Answer: Yes

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Row 6:

Circuit 11 (Left):
- Battery, bulb, and an open switch.
- Switch is open → gap in circuit → no current.
- Answer: No

Circuit 12 (Right):
- Only a bulb, no battery, no power source.
- Answer: No

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✔ Final Answers:

| Circuit | Answer |
|--------|--------|
| 1 | Yes |
| 2 | No |
| 3 | No |
| 4 | No |
| 5 | Yes |
| 6 | No |
| 7 | No |
| 8 | No |
| 9 | No |
| 10 | Yes |
| 11 | No |
| 12 | No |

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Summary of Answers:

Column 1 (Left Side):
1. Yes
2. No
3. Yes
4. No
5. No
6. No

Column 2 (Right Side):
1. No
2. No
3. No
4. No
5. Yes
6. No

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✔ Final Check:

Let’s list them clearly:

Left Column:
1. Battery + bulb → Yes
2. Bulb only → No
3. 3 batteries + bulb → Yes
4. Battery + open switch + bulb → No
5. Two bulbs in parallel, no battery → No
6. Battery + open switch + bulb → No

Right Column:
1. Two batteries in opposing directions → No
2. Battery + bulb + open switch → No
3. Two batteries in parallel? But no bulb → No
4. Batteries opposing or shorted → No
5. Battery + bulb + bulb + bulb in series → Yes
6. Bulb only → No

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✔ Final Answer Grid:

| Circuit | Will the bulb light? |
|--------|----------------------|
| 1 | Yes |
| 2 | No |
| 3 | Yes |
| 4 | No |
| 5 | No |
| 6 | No |
| 7 | No |
| 8 | No |
| 9 | No |
| 10 | Yes |
| 11 | No |
| 12 | No |

> Note: For clarity, I’ll number them as per the grid:

- Row 1, Col 1: Yes
- Row 1, Col 2: No
- Row 2, Col 1: No
- Row 2, Col 2: No
- Row 3, Col 1: Yes
- Row 3, Col 2: No
- Row 4, Col 1: No
- Row 4, Col 2: No
- Row 5, Col 1: No
- Row 5, Col 2: Yes
- Row 6, Col 1: No
- Row 6, Col 2: No

✔ These are the correct answers based on basic circuit principles.