A gap anywhere in a circuit stops the bulb from lighting, even if every other wire is connected.

Circle one:   True   False

Look at this circuit. Trace the loop: cell, wire, bulb, wire, back to the cell, with no gaps. Will the bulb light up?

• Yes, the loop is complete so it will light
• No, it needs a switch to work
• It depends on how long the wires are

What should you check first to tell if a bulb will light up?

• How bright the light bulb looks
• Whether the loop connects all the way around with no gaps
• What color the wires are

Priya's wire looks like it's touching the bulb, but it's actually resting just next to it, not making contact. What happens?

• The bulb stays off, because that's still a gap
• The bulb lights dimly
• The bulb lights normally, since the wire is close enough

Tom's circuit has a cell, a wire, and a bulb, but there's no wire connecting the bulb back to the cell. Will the bulb light?

• Yes, one wire is enough
• Yes, the bulb doesn't need to connect back
• No, the loop never gets back to the cell

Look at this circuit. There is one spot where the pieces are not touching. Will the bulb light up?

• Yes, because the rest of the loop connects fine
• No, that one gap breaks the whole loop
• Yes, gaps only matter near the bulb

Circuit A: cell, wire, bulb, wire, all connected back to the cell. Circuit B: the same parts, but one wire's end just rests near the cell without touching it. Which circuit lights up?

• Only Circuit A
• Both light up the same way
• Only Circuit B

This circuit does not light up: cell, wire, bulb, wire, then a gap right before the loop reaches the cell again. What is the fault?

• The bulb is broken
• The cell is too weak
• The last connection back to the cell is missing