The AC Transformer

Learn how voltage is stepped up or down using mutual induction.

The Concept: Mutual Induction

A transformer uses two coils, a primary and a secondary, wrapped around a common iron core. An alternating current in the primary coil creates a continuously changing magnetic field in the core. This changing flux passes through the secondary coil, inducing a voltage in it via Faraday's Law. The ratio of the output voltage to the input voltage is determined by the ratio of the number of turns in the coils.

How to Use the Lab

Observe the animated current and the changing magnetic flux in the iron core.
The secondary coil is connected to a light bulb, which glows based on the output voltage.
Adjust the number of turns on the Primary Coil ($N_p$) and the Secondary Coil ($N_s$).
The voltage graphs provide a real-time comparison of the input and output on the same dynamic scale.

Controls

Primary Turns ($N_p$): 10

Secondary Turns ($N_s$): 5

Transformer Equation

$\frac{V_s}{V_p} = \frac{N_s}{N_p}$

The AC Transformer

The Concept: Mutual Induction

How to Use the Lab

Controls

Transformer Equation

Primary Voltage ($V_p$)

Secondary Voltage ($V_s$)