Ohm's Law Lesson | BCHydro Power Smart for Schools

Ohm's Law

Understand the relationship between voltage, current and resistance, then create and test circuits in small groups.

  • Grade 9
  • 2 activities
  • 1.3 hours
Lesson Image

Big idea

Electric current is the flow of electric charge.

Learning objectives

Students will be able to:

  • Demonstrate the relationship between voltage, current and resistance.
  • Solve for an unknown value using Ohm’s Law.


BC curriculum fit

Grade 9 Science 


  • Voltage, current and resistance
  • Circuits

Curricular competencies

Questioning and predicting
  • Demonstrate a sustained intellectual curiosity about a scientific topic or problem of personal interest
  • Make observations aimed at identifying their own questions, including increasingly complex ones, about the natural world
Planning and conducting
  • Collaboratively and individually plan, select, and use appropriate investigation methods, including field work and lab experiments, to collect reliable data (qualitative and quantitative)

Background info

Ohm’s Law shows the relationship between voltage and current. It’s usually shown as a mathematical relationship with the formula V = I x R, where V is voltage, I is current, and R is resistance. Resistance is the ratio of voltage to current and the formulas below allow us to calculate any one unknown value: 


During group work, note the students’ abilities to build and test for resistance in a circuit. Worksheet activities allow students to show their understanding of the relationship between current and voltage and their ability to  calculate an unknown value in the Ohm’s Law equation. 

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