Reading and drawing circuit diagrams

Science · Energy · ages 9-10

Name ______________________ Date ____________

In her circuit diagram, Priya draws the power source as one long line next to one short line. Which part has she drawn?
- A bulb
- A cell
- A switch
Which symbol stands for a bulb in a circuit diagram?
- A circle with an X inside
- Two lines, one long and one short
- A zigzag line
In a circuit diagram, plain straight lines stand for wires.
Circle one: True False
A circuit diagram shows the switch lever touching the line, closing the gap. What does this mean for the bulb?
- The bulb stays dark
- The bulb lights up because the loop is complete
- The bulb only lights halfway
A circuit diagram shows a switch with a gap between the lever and the line. What does this mean for the bulb?
- The bulb lights because the loop is complete
- The bulb stays dark because the switch is open
- The bulb flickers on and off
A photo shows a real circuit with a closed switch and a bulb that is lit. Which circuit diagram matches this photo?
- A diagram with a closed switch and no gaps in the loop
- A diagram with an open switch
- A diagram with the cell missing
A photo shows a real circuit with a closed switch, but the wire has come loose from the bulb, so the bulb is dark. Which diagram matches this photo?
- A diagram with an open switch and no bulb
- A diagram with a closed switch and no gaps
- A diagram with a closed switch but a gap in the loop
Zoe draws a circuit diagram with a closed switch, but she leaves a small gap between the bulb symbol and one wire. Will the bulb really light?
- Yes, because the switch is closed
- No, because the gap near the bulb breaks the loop
- Yes, because gaps only matter at the switch

Answer key

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

Reading and drawing circuit diagrams W1-mt_loYPGHJ8lm-s1

A cell · Two lines, one long and one short, are the symbol for a cell, the part that powers the circuit.
A circle with an X inside · The circle with an X inside is the standard symbol for a bulb.
True · Straight lines connect the symbols and show where the wires run.
The bulb lights up because the loop is complete · A closed switch joins the loop, so electricity can flow all the way around and light the bulb.
The bulb stays dark because the switch is open · A gap at the switch breaks the loop, so no electricity can reach the bulb.
A diagram with a closed switch and no gaps in the loop · A lit bulb means the loop is complete, so the matching diagram shows a closed switch with no gaps.
A diagram with a closed switch but a gap in the loop · A closed switch alone is not enough. The loose wire leaves a gap, so the matching diagram needs a gap too, even with the switch closed.
No, because the gap near the bulb breaks the loop · Every connection in the loop must be complete. A gap anywhere, even away from the switch, stops the electricity.