Physics ELECTRO MAGNETIC INDUCTION

Please Wait... While Loading Full Video

ELECTRO MAGNETIC INDUCTION

Induced EMF

Whenever the flux of magnetic field through the area bounded by a closed conducting loop changes, an emf is produced in the loop. The emf is given by

`epsilon=-(dphi)/(dt)`

The -ve sign is according to Lenz's law.

For a coil that consists of N loops, the induced emf would be `=>` `epsilon=-N(dphi)/(dt)`

Average emf is is given by `=>` `epsilon=-(Deltaphi_B)/(Deltat)`

Whenever the flux of magnetic field through the area bounded by a closed conducting loop changes, an emf is produced in the loop. The emf is given by

`epsilon=-(dphi)/(dt)`

The -ve sign is according to Lenz's law.

For a coil that consists of N loops, the induced emf would be `=>` `epsilon=-N(dphi)/(dt)`

Average emf is is given by `=>` `epsilon=-(Deltaphi_B)/(Deltat)`

Induced Current

Just as a current flowing through a wire will produce a magnetic field, so a wire moving through a magnetic field will have a current flowing through it. This is called electromagnetic induction and the current in the wire is called induced current.

A stationary wire in the presence of a changing magnetic field also has an induced current.

A changing magnetic field can be produced either by moving a magnet near to the stationary wire or by using alternating current.

A stationary wire in a magnetic field which is not changing will have no current induced in it.

You will sometimes see this effect described as induced voltage. Strictly speaking, you will only get an induced current in the wire if it is part of a complete circuit.

A wire which is unconnected at both ends will have a difference in voltage between the ends (a potential difference) but current can only flow when the wire is in a circuit.

Induced current is used in electricity generation and transformers.

`text(Induced current is given by :)`

`i=-1/R (dphi_B)/(dt)`

`text(Charge flown through a coil :)`

`Deltaq=intidt=int_(t_1)^(t_2)-1/R (dphi_B)/(dt) dt=1/Rint_(phi_1)^(phi_2)-dphi`

`Deltaq=(phi_2-phi_1)/R`

Just as a current flowing through a wire will produce a magnetic field, so a wire moving through a magnetic field will have a current flowing through it. This is called electromagnetic induction and the current in the wire is called induced current.

A stationary wire in the presence of a changing magnetic field also has an induced current.

A changing magnetic field can be produced either by moving a magnet near to the stationary wire or by using alternating current.

A stationary wire in a magnetic field which is not changing will have no current induced in it.

You will sometimes see this effect described as induced voltage. Strictly speaking, you will only get an induced current in the wire if it is part of a complete circuit.

A wire which is unconnected at both ends will have a difference in voltage between the ends (a potential difference) but current can only flow when the wire is in a circuit.

Induced current is used in electricity generation and transformers.

`text(Induced current is given by :)`

`i=-1/R (dphi_B)/(dt)`

`text(Charge flown through a coil :)`

`Deltaq=intidt=int_(t_1)^(t_2)-1/R (dphi_B)/(dt) dt=1/Rint_(phi_1)^(phi_2)-dphi`

`Deltaq=(phi_2-phi_1)/R`

SiteLock