## 30.2:

JoVE Core
Physik
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JoVE Core Physik

### Nächstes Video30.3: Lenz’s Law

Faraday's law states that in a closed conducting loop, the induced emf equals the negative time derivative of the magnetic flux through that loop. The direction of the induced emf was later given by Lenz.

If the conducting loop consists of N number of identical turns and the flux passing through each one is the same, then the total magnetic flux is N times the magnetic flux through each turn. Hence, the total induced emf will be N multiplied by the rate of change of magnetic flux.

Consider a square coil of length 0.25 meters, which consists of closely wound 500 turns of wire. This coil is placed in the magnetic field that is increasing with the rate of 0.2 tesla per second.

Then the magnitude of induced emf in the coil can be calculated using Faraday's law. Substituting the values, the magnitude of the induced emf can be estimated.

It is important to observe that the emf can be induced by changing any one of these parameters or a combination of them.