Resistance Reduction Repair
Subject:
Grade Level:
STEM
9-12
National Career Cluster:
National Career Pathway:
Architecture & Construction
Construction
Manufacturing
Maintenance, Installation & Repair
Science, Technology, Engineering & Mathematics
Engineering and Technology
Primary Common Core State Standards
Algebra: Creating Equations - Create equations that describe numbers or relationships (Math - High
School)
2. Create equations in two or more variables to represent relationships between quantities; graph equations on
coordinate axes with labels and scales.
Algebra: Creating Equations - Create equations that describe numbers or relationships (Math - High
School)
4. Rearrange formulas to highlight a quantity of interest, using the same reasoning as in solving equations. For
example, rearrange Ohm’s law V = IR to highlight resistance R.
Other Related Common Core State Standards:
Number and Quantity: Quantities - Reason quantitatively and use units to solve problems. (Math - High
School)
1. Use units as a way to understand problems and to guide the solution of multi-step problems; choose and
interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.
Next Generation Assessment:
Resistance is the opposition to the flow of electrical current. An electrician wants to replace an electrical wire used in a simple circuit with a
wire that has less resistance to current flow. The diagram shows the simple circuit the electrician is working on.
The wire that the electrician is replacing is between points X and Y. The old wire was 15 feet long and made of copper. Previously, when one
volt was applied, 60 amps of current flowed through the circuit. The electrician plans to install another copper wire in the circuit but is not sure
if he should use a longer or shorter wire to decrease resistance.
Ohm’s law can be used to determine the relationship between voltage, current, and resistance: V = IR, where V is the current in
volts, I is the current in amps, and R is the resistance in ohms.
1. How can the electrician manipulate Ohm’s law to determine the resistance of the previous wire?
2. How can you use a graph to illustrate the relationship between wire length and resistance? Construct a graph using at
least three data points.
3. How can use your graph to help the electrician decide between a cooper wire that is longer or shorter than 15 feet?
Explain your reasoning.
Write a memo to the electrician with your findings and recomendations. Justify your findings.
Duration:
Student Work:
Criteria for Student Learning:
Resources students will be provided or will
have to acquire:
about 30 minutes
Graph
Real-world problem solutions
1. Manipulate Ohm’s law for resistance
2. Graph wire length versus resistance
3. Determine wire length that provides less resistance
4. Memo is error free with justifications for findings
calculator, graph paper
art 1_simple circuit.docx
Scoring Guide
1. R = V / I
2. The graph should show that as wire length increases, resistance increases.
3. shorter than 15 feet; wire length and resistance are directly related
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