Warning: Do not skip this step! Without the resistor, there is a risk that the LED could break when plugged into power.
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Insert one end of the resistor into any hole in the red row of the breadboard. Remind students the red wire and resistor are now connected (holding hands).
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Insert the other end of the resistor into any hole in the blue row of the breadboard.
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Use the blue marker to mark this on the schematic as shown in the video.
STEM Connections
A resistor needs to be added to a circuit because LEDs can be damaged when too much electric current flows through them. How much a resistor reduces the flow of electric current is known as the resistance and is measured in a unit called Ohms. The resistance of a resistor is indicated by colored lines on the resistor.
At the Thinkabit Lab, we use the schematic of the circuit to engage students in the following discussion:
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Explain to students that since the schematic is colored red on one side of the resistor, we will connect one side of the resistor to the red row.
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Ask students: “Where in the breadboard do you think the other side of the resistor should go?”
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Students will likely answer the blue or black row.
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Explain to students that if we connected the resistor to the black row, that would complete the circuit and skip the LED altogether, so we need to use a different row. Therefore, we need to use the blue row
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Write out “Resistor: red row – blue row”
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Using a blue marker to color the connection from the resistor to the LED is a way to show students where components belong on the breadboard.
If you are using the Thinkabit Lab Notebook:
Have students fill in the blank on page 13 after “Resistor” with “red row to blue row” and color their schematic.
Resistor: red row to blue row
Resistor legs are bent
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The legs of the resistor can be bent or reshaped, as needed.
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Replace the resistor if it breaks. It is normal for the resistor to break after repeated reshaping of the legs.
Resistor doesn’t fit into the breadboard
- Try a different hole in the same row of the breadboard