This document summarizes Faraday's experiment to demonstrate that a changing magnetic field can induce an electric current. The experiment uses wires, a voltmeter, two solenoids, a potential difference generator, and a U-shaped ferromagnetic core. When the generator is switched on and off, creating a changing magnetic field, the voltmeter detects a small current in the other solenoid for a brief period, in accordance with Faraday's law of induction. The results confirm that a changing magnetic flux generates an induced current.

1. Faraday’s experiment
Knowledge required
Definition of flux, magnetic and electric field.
Purpose
It demonstrate that a magnetic field can generate induced current.
Materials
-Wires;
-Voltmeter;
-2 solenoids;
-Potential difference generator;
-“U” shaped ferromagnetic core.
Procedure
First of all, you have to put the two solenoids into the “U” shaped
ferromagnetic core, then we link one of the solenoids to the generator
and the other to the voltmeter. After we have attached the wires, we
switch on and off the generator to see what happens.
Observation
You will notice that turning on and off the generator, the voltmeter
marks a low current for a small period of time, but if we stop, it marks
no current.

2. Calculations
From this observation you understand that:
|ΔV| = ΔΦ(B) / Δt -> ΔV = -ΔΦ(B) / Δt Faraday’s law
The minus came from the Lenz’s law, which establishes that induced
current is directed to oppose the change in flux and to exert a
mechanical force which opposes the motion due to a change in a
magnetic field.
Conclusions
Thanks to this experiment, we have demonstrated that the current is
produced by the changing of a magnetic field flux.