Transformers

Definition

Transformers are devices used to increase or decrease the voltage of alternating current (AC) in electrical circuits. They operate on the principle of electromagnetic induction to transfer electrical energy between two or more coils.

5 Must Know Facts For Your Next Test

1. Transformers consist of primary and secondary coils wrapped around a magnetic core.
2. The voltage ratio between the primary and secondary coils is proportional to the number of turns in each coil, expressed as $\frac{V_p}{V_s} = \frac{N_p}{N_s}$.
3. Ideal transformers assume no energy loss, but real transformers experience losses due to resistance, hysteresis, and eddy currents.
4. Step-up transformers increase voltage while decreasing current, and step-down transformers decrease voltage while increasing current.
5. Transformers are crucial for the efficient transmission of electrical power over long distances, reducing energy losses.

Review Questions

• What is the main principle that allows transformers to work?
• How does the number of turns in the primary and secondary coils affect the voltage in a transformer?
• Why are transformers important for long-distance power transmission?

Related terms

Electromagnetic Induction:

The process by which a changing magnetic field within a conductor induces an electric current.

AC Circuits: Electrical circuits powered by alternating current (AC), where the flow of electric charge periodically reverses direction.

Magnetic Core: A material with high magnetic permeability used in transformers to channel magnetic flux efficiently between coils.