Learn: The Motor Effect

Welcome!Today we'll explore the motor effect, a key concept in Physics. This is an important topic in the AQA GCSE Combined Science specification, and you'll learn how magnetic fields interact to produce forces. Let's get started!

What is the Motor Effect?The motor effect occurs when a current-carrying wire is placed in a magnetic field. The wire experiences a force due to an interaction between the magnetic field and the current. This is the basis for many devices, like electric motors.

How Does It Work?When an electric current flows through a wire, it creates its own magnetic field. If this wire is placed in another magnetic field (e.g., from a magnet), the two fields interact. This interaction produces a force that pushes the wire.

How Is the Force Created?The force is created because the magnetic field around the wire interacts with the external magnetic field. The direction of the force depends on the direction of the current and the magnetic field. This is explained by Fleming's left-hand rule.

Fleming's Left-Hand RuleFleming's left-hand rule helps determine the direction of the force. Your thumb, first finger, and second finger represent the force, magnetic field, and current, respectively. Align your fingers correctly, and you'll know which way the wire will move.

Factors Affecting the ForceThe size of the force depends on three factors: the strength of the magnetic field, the amount of current in the wire, and the angle between the wire and the magnetic field. A greater current or stronger magnetic field produces a larger force.

Real-World ApplicationsThe motor effect is used in devices such as electric motors, loudspeakers, and maglev trains. For example, in an electric motor, the force causes the rotor to spin, creating motion that can be used in machinery.

Review Time!Great work! You've learned about the motor effect, how it works, and its applications. Let's test your understanding with a few more questions.