Electricity and Circuits — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. In a series circuit, electricity follows one single path.
A series circuit has only one path for current. All components are connected end-to-end in a single loop.
2. In a parallel circuit, electricity has two or more paths to follow.
A parallel circuit splits the current into two or more branches, each providing a separate path.
3. If one bulb burns out in a series circuit, all the other bulbs go out.
In a series circuit, one failure opens the entire path, stopping current from reaching all other components.
4. If one bulb burns out in a parallel circuit, the other bulbs stay on.
In a parallel circuit, each branch is independent. A break in one branch doesn't affect the others.
5. The lights in most homes are wired in parallel circuits.
Home wiring is parallel so that turning off or replacing one light doesn't affect the others.
6. A string of old holiday lights that all go out when one breaks is a series circuit.
Old-style holiday lights are wired in series — one broken bulb opens the single path, turning all lights off.
7. Adding more bulbs to a series circuit makes each bulb shine dimmer.
More bulbs in series means the voltage is divided among them, so each bulb receives less and shines dimmer.
8. The unit used to measure electric current is the ampere.
Current is measured in amperes (amps), named after physicist André-Marie Ampère.
9. A device that opens a circuit when too much current flows is called a fuse.
A fuse contains a thin wire that melts and breaks the circuit if current exceeds a safe level, preventing fires.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
battery
→ provides energy to push current
blocks the flow of electricity
switch
→ opens and closes a circuit
provides energy to push current
conductor
→ allows electricity to pass through
allows electricity to pass through
insulator
→ blocks the flow of electricity
opens and closes a circuit
Battery → provides energy; switch → opens/closes circuit; conductor → allows flow; insulator → blocks flow.