# Ohm's Law

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

• 2 Activities
• 1.3 hours

#### 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

#### 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:

#### Assessments

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.

#### Grade 9 Science - Content

• Voltage, current and resistance
• Circuits

#### Grade 9 Science - 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)