- FARADAYS LAWS OF ELECTROMAGNETIC INDUCTION
- LENZS LAW (CONSERVATION OF ENERGY PRINCIPLE)
- MOTIONAL EMF
- EXPLANATION OF EMF INDUCED IN ROD ON THE BASIS OF MAGNETIC FORCE
- INDUCED EMF DUE TO ROTATION
- EMF INDUCED IN A ROTATING DISC
- FIXED LOOP IN A VARYING MAGNETIC FIELD
- SELF INDUCTION
- SELF INDUCTANCE OF SOLENOID
- INDUCTOR
- ENERGY STORED IN AN INDUCTOR
- GROWTH OF CURRENT IN SERIES R–L CIRCUIT
- DECAY OF CURRENT IN THE CIRCUIT CONTAINING RESISTOR AND INDUCTOR
- MUTUAL INDUCTANCE
- TRANSFORMER
- ENERGY LOSSES IN TRANSFORMER

When magnetic flux passing through a loop changes with time or magnetic lines of

force are cut by a conducting wire then an emf is produced in the loop or in that

wire. This emf is called induced emf.

Read moreAccording to this law, emf will be induced in such a way that it will oppose the cause which has

produced it. Figure shows a magnet approaching a ring with its north pole towards the ring

Read moreWe can find emf induced in a moving rod by considering the number

of lines cut by it per sec assuming there are ‘B’ lines per unit

area. Thus when a rod of length moves with velocity v in a magnetic

field B, as shown, it will sweep area per unit time equal to v

and hence it

Read moreEXPLANATION OF EMF INDUCED IN ROD ON THE BASIS OF MAGNETIC FORCE

Read moreROTATION OF THE ROD

Consider a conducting rod of length l rotating in a uniform magnetic field.

Read moreConsider a disc of radius r rotating in a magnetic field B.

Consider an element dx at a distance x form the centre. This element is moving with

Read moreNow consider a circular loop, at rest in a varying magnetic field. Suppose the magnetic field is

directed inside the page and it is increasing in magnitude. The emf induced in the loop will be

Read moreSelf induction is induction of emf in a coil due to its own current change.Total flux N?

passing through a coil due to its own current is proportional to the current and is given as N

L i where L is called coefficient of self induction or inductance.The inductance L is purely

Read moreLet the volume of the solenoid be V , the number of turns per unit length be n.

Let a current I be flowing in the solenoid.Magnetic field in the solenoid is given as

Read moreIf current i through the inductor is increasing the induced emf will oppose the increase in

current and hence will be opposite to the current.If current i through the inductor is decreasing

the induced emf will oppose the decrease in current and hence will be in the direction of the

current.

Read moreIf current in an inductor at an instant is i and is increasing at the rate di/dt,the induced emf

will oppose the current . Its behaviour is shown in the figure.

Read moreFigure shows a circuit consisting of a cell, an inductor L and a resistor R ,connected in series. Let the

switch S be closed at t=0.Suppose at an instant current in the circuit be i which is increasing at the rate

di/dt.

Read moreDECAY OF CURRENT IN THE CIRCUIT CONTAINING

RESISTOR AND INDUCTOR

Read moreConsider two arbitrary conducting loops 1 and 2. Suppose that ?1 is the instantaneous current flowing around

loop 1. This current generates a magnetic field B1 which links the second circuit, giving rise to a magnetic flux ?2

through that circuit. If the current ?1doubles, then the magnetic field B1 doubles in strength at all points in space,

so the magnetic flux ?2 through the second circuit also doubles. Furthermore, it is obvious that the flux through

the second circuit is zero whenever the current flowing around the first circuit is zero. It follows that the flux ?2

Read moreA transformer changes an alternating potential difference from one value to another of greater or

smaller value using the principle of mutual induction .Two coils called the primary and secondary

windings,which are not connected to one another in any way , are wound on a complete soft iron

core.When an alternating voltag

Read moreAlthough transformers are very efficient devices, small energy losses do occur in them due to four main causes.

1. RESISTANCE OF THE WINDINGS

Read more