Introduction
 

Current–voltage (I–V) characteristics describe how electrical components respond to changes in potential difference and current. Understanding these relationships is essential for analysing electrical circuits and predicting the behaviour of components such as resistors, filament lamps and diodes.
 

In this topic, students learn how to interpret I–V graphs, distinguish between ohmic and non-ohmic conductors, and apply the basic principles of current, potential difference and resistance. These ideas form the foundation for more advanced studies of electricity throughout the AQA A Level Physics course.
 

AQA A Level Physics Specification: 3.2.4.1 Current, Potential Difference and Resistance
 

What You Need to Know
 

• Define electric current as the rate of flow of charge.

• Define potential difference as the energy transferred per unit charge.

• Define resistance and apply Ohm's Law.

• Understand the difference between ohmic and non-ohmic conductors.

• Describe and interpret the I–V characteristics of:

  • Ohmic conductors (fixed resistors)

  • Filament lamps

  • Diodes

• Explain why the resistance of a filament lamp changes with temperature.

• Understand the function of a diode and why it only allows current to flow in one direction.

• Interpret and compare I–V characteristic graphs.

• Apply the relationship between current, potential difference and resistance when solving calculations.
   

Downloadable Topic Pack

IV Characteristics and Electricity Basics Topic Pack Exam Questions and Answers 
 

Related Topics

• Resistivity

• Electrical Power

• Internal Resistance

• Potential Divider

• EMF and Cells