Indiana Science HS-PSII-6.2
The Standard
Develop and apply a mathematical representation that describes the relationship between the magnetic field created by a long straight wire carrying an electric current, the magnitude of the current, and the distance to the wire.
Indiana Academic Standards for Science (2023) · Magnetism
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students graph magnetic field strength against current and inverse distance for a long, straight wire. They use the patterns to write an equation and predict field strength.
What Mastery Looks Like
- Students use B = μ₀I/(2πr) to calculate field strength, with current in amps and distance in meters. They explain why doubling current doubles the field, while doubling distance halves it.
Common Misconceptions
- Students may assume the field drops with distance squared or stays the same at every distance. Some measure distance along the wire instead of straight out from it.
How to Assess It
- Exit ticket: At 2 A, a wire's field is 8 μT at 5 cm. What is the field at 20 cm if current rises to 4 A? Show your calculation.
Lesson moves
Ways to Teach It
With a field sensor and current-limited supply, measure field at 2, 4, and 8 cm from a wire; subtract the background reading.
Ask, 'If current doubles and distance triples, how does the field change?' Have students justify their answer using I/r.
Give pairs cards showing different currents and distances; have them rank the predicted field strengths using I/r.
Use a sketch of one long power-line conductor to compare predicted field strengths 5 m and 10 m away at the same current.
Free download
Printable HS-PSII-6.2 Worksheet
A ready-to-print activity worksheet aligned to HS-PSII-6.2, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetKeep exploring
Related Standards
- HS-PSII-5.2
Develop graphical and mathematical representations that describe the relationship between the between the amount of current passing through an ohmic device and ...
- HS-PSII-4.2
For a single isolated charge, develop and apply graphical and mathematical representations that describe the relationship between the amount of charge, the dist...
- HS-PSII-7.2
Develop graphical and mathematical representations that describe the relationship between the rate of change of magnetic flux and the amount of voltage induced ...
- HS-PSII-7.3
Apply Ohm's Law, Faraday's Law, and Lenz's Law to determine the amount and direction of current induced by a changing magnetic flux in a loop of wire or simple ...
Turn this exact standard into a lesson
Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.
Also for this standard:Make a WorksheetMake a QuizMake a Sub Lesson