# Lesson Plan: Electrical Resistance Science

This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to define electrical resistance and how it affects the flow of charge within a circuit.

#### Objectives

Students will be able to

• understand that electrical resistance is the opposition to the flow of charges within a conductor,
• understand that very large currents can cause wires to heat up,
• know that resistance can be measured in ohms,
• know that resistance can be measured using an ohmmeter,
• understand that if there is a potential difference across a component of one volt and the current through it has a value of one amp, then the resistance of the component is one ohm,
• identify the circuit symbol for a resistor,
• identify the circuit symbol for a variable resistor,
• understand that the resistance of a wire increases if the length of the wire increases.

#### Prerequisites

Students should already be familiar with

• what electric charge is,
• what electric current is,
• what electric potential difference is,
• using ammeters to measure current,
• using voltmeters to measure potential difference,
• the circuit symbols for a cell, a battery, an ammeter, a voltmeter, and a bulb.

#### Exclusions

Students will not cover

• electrical conductance,
• how ohmmeters work,
• thermistors,
• light-dependent resistors,
• the current–voltage characteristics of different components,
• resistivity and conductivity,
• resistors in series or in parallel,
• resistance in alternating current circuits,
• internal resistance of cells,
• interpreting resistor markings.