CHE 1403: Circuits
Purpose:
Students will learn the relationship between voltage, current and resistance by exploring series and parallel circuits. Students will design and answer their own question.
Background:
Ohm’s Law describes the relationship between current, voltage, and resistance.
V = I R
For this lab, the resistance is provided by the light bulbs. Fortunately, the light bulbs can light up different amounts, which allows us to approximate the amount of power used. Based on your observations and calculations, you will be able to determine whether voltage or current controls the brightness of the light bulbs.
During this lab, we will also construct more complicated circuits known as ‘series’ and ‘parallel’. A series circuit has the electricity flowing through all elements, one after another, while a parallel circuit has multiple paths for the electricity to flow.
You will also generate a scientific question and then answer it using the circuit materials. When forming this question, remember to include ideas of independent, dependent, and controlled variables. Only one thing in your circuits should change at a time, so that you can be certain that any change in results is caused by the change you made in the circuit elements.
Procedure:
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Use the kit instructions to build a simple circuit with one battery, battery holder, and light bulb. Note your observations:
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Add a switch to your circuit.
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When the switch is swung away from the other side, does the bulb light? Is this circuit open or closed?
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When the switch is swung into from the other side (touching), does the bulb light? Is this circuit open or closed?
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Note any other observations. Particularly, compare with the circuit with no switch.
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Create the first series and parallel circuit from the kit instructions. For each circuit, record your observations:
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Compose a scientific question related to series and/or parallel circuits and your observations. What can you change about the circuit? Remember to change only one variable at a time. Have the instructor approve your question before proceeding.
What circuits will you need to build to test/answer your question? Draw them below
DETAILED ASSIGNMENT
