Building a simple circuit · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Building a simple circuit

Science · Energy · ages 8-9
Name ______________________   Date ____________

  1. Which part lets you open or close the circuit?

    • The bulb
    • A switch
    • The wire

  2. What is the part of a circuit that pushes electricity through the wires?

    • The cell (battery)
    • The wire
    • The switch

  3. A circuit needs a complete loop with no gaps for electricity to flow.

    Circle one:   True   False

  4. Sam builds a loop with a cell, wires, and a buzzer, but one connection is missing. What happens?

    • The buzzer makes no sound because the loop is broken
    • The buzzer gets louder
    • The buzzer works fine anyway

  5. Ana connects a cell, two wires, and a bulb in a loop, but forgets to add a switch. Can the bulb still light up?

    • No, a circuit cannot work without a switch
    • Only if the wire is very short
    • Yes, the bulb can light without a switch

  6. Look at the loop. How many wires are used to connect the parts?

    cellwireswitchwirebulbwire

    Answer: ______________

  7. Which of these would still work as a simple circuit part in place of a bulb?

    • A second cell with no wire attached
    • A wire with a gap in the middle
    • A buzzer, because it also uses the electricity that flows through the loop

  8. Mia's circuit has a cell, a closed switch, wires, and a bulb, but one wire is cut in half with the two ends not touching. What happens when Mia closes the switch?

    • The bulb will light because the switch is closed
    • The bulb stays dark; the loop still has a gap
    • The bulb will light dimly
LightMySky · lightmysky.comW1-mt_DA7-JYRvtP-s1

Answer key

For grown-ups. Fold this page away before handing over the rest.

Building a simple circuit W1-mt_DA7-JYRvtP-s1

  1. A switch · The switch makes or breaks the gap in the loop.
  2. The cell (battery) · The cell (battery) is what pushes the electricity around the loop.
  3. True · Any gap stops the flow, so the loop must be complete.
  4. The buzzer makes no sound because the loop is broken · A missing connection breaks the loop, so the electricity cannot reach the buzzer.
  5. Yes, the bulb can light without a switch · A switch is handy for turning the circuit on and off, but a bulb can still light without one as long as the loop is complete.
  6. 3 · Count each piece labeled wire in the loop: there are 3.
  7. A buzzer, because it also uses the electricity that flows through the loop · A buzzer, like a bulb, is something the circuit powers. It just makes sound instead of light.
  8. The bulb stays dark; the loop still has a gap · Closing the switch is not enough. Every part of the loop, including the cut wire, must be connected for electricity to flow.
Worksheet · LightMySky