Electromagnetic induction in transformers

How Electromagnetic Induction Works

Electromagnetic induction happens when a magnetic field and an electrical conductor (like a wire) move relative to each other. This means the magnetic field around the wire changes, which creates a potential difference (voltage). If the circuit is complete, this makes an electric current flow.

Opposition to the Change

When a current is induced in a wire, the current creates its own magnetic field. This new magnetic field opposes the change that caused it, acting as a resistance to the movement that generated the current.

Transformers – How They Work

Transformers consist of:

• Primary coil: The coil where alternating current (AC) flows in.
• Secondary coil: The coil where the transformed voltage comes out.
• Iron core: A soft iron core links the magnetic field between the two coils and ensures efficient transfer of energy.

When AC flows into the primary coil, it creates a changing magnetic field. This magnetic field passes through the iron core and induces a voltage in the secondary coil through electromagnetic induction.

Step-Up and Step-Down Transformers

• Step-Up Transformer: Increases the voltage by having more turns of wire in the secondary coil than the primary coil. This type is used to send electricity efficiently over long distances.
• Step-Down Transformer: Decreases the voltage by having fewer turns of wire in the secondary coil. It makes electricity safe for use in homes and devices.

Efficiency of Transformers

In real-life applications, transformers are highly efficient, but they are not 100% efficient. Some energy is lost as heat in the coils and the core. Despite this, most energy is transferred between the coils, making transformers vital for power transmission.