formula.expert

Faraday's Law of Induction

Also known as electromagnetic induction · induced EMF

ε=NΔΦΔt\varepsilon = N \frac{\Delta\Phi}{\Delta t}

Enter your known values, leave one input blank, and solves for the missing one. Try different units for next level excitement!

Learning zone

Faraday's 1831 discovery is the bridge between mechanics and electricity: change the flux through a coil and a voltage appears, one volt per weber-per-second per turn. The N multiplies because each turn is a voltage source in series — the reason transformers and generators are wound with hundreds of turns. Sweep a magnet that changes flux by 2 mWb through a 500-turn coil in 0.1 s and you induce 10 V.

The full law carries a minus sign (Lenz's law): the induced current always opposes the change that created it — nature's built-in inertia against flux change, and the origin of eddy-current braking.

Faraday's Law of Induction
ε=NΔΦΔt\varepsilon = N \frac{\Delta\Phi}{\Delta t}
Where
  • ε\varepsilon= Induced EMF
  • NN= Number of turns
  • ΔΦ\Delta\Phi= Flux change
  • Δt\Delta t= Time interval
Missing one of these? Work it out first, then come back