GCSE PHYSICS - MAGNETISM AND ELECTROMAG - LESSON 16 - electromagnetic induction loop ´- part 2

Electromagnetic Induction in Loops and Solenoids

Introduction to Electromagnetic Induction

• The lesson focuses on electromagnetic induction, specifically in loops, coils, or solenoids.

• Previously learned that moving a conducting cable through a magnetic field induces an electrical potential difference (voltage).

Understanding Current Generation

• A single cable generates voltage but does not produce current; a closed circuit is necessary for current flow.

• By forming a loop with the cable, the induced voltage can drive current around the loop.

Direction of Current Flow

• Electron flow direction is established as negative charge moves towards one end of the loop.

• Conventional current flows from positive to negative; thus, pushing the loop into the magnetic field causes anti-clockwise current flow.

Alternating Current Concept

• Reversing the loop's direction changes the sign of induced voltage and electron flow direction.

• An ammeter inserted in this setup would show alternating current as it flips between positive and negative when moving in and out of the magnetic field.

Enhancing Electrical Potential Difference

• A single conducting loop produces limited voltage; increasing loops forms a coil or solenoid to enhance potential difference.

• Each section of the solenoid cutting through the magnetic field generates individual voltages that add up in series.

Factors Affecting Voltage Generation

• The total induced voltage depends on:

• Speed of conductor cutting through magnetic fields: faster movement increases current.

• Strength of magnetic field: stronger fields yield larger currents.

• Number of loops in solenoid: more turns lead to greater generated electrical potential difference.