Electromagnetic Induction Flashcards
The SI unit of magnetic flux is
weber
the flux linked with a cell can be increased by
keeping the coil in a time varying magnetic field
keeping the coil in a magnetic field
by changing area of the coil in a uniform magnetic field
the direction of induced current can be determined by
Lenz’s law
in the phenomenon of electromagnetic induction _____energy is transformed into ______ energy
mechanical into electrical
The self inductance of a coil does not depend upon
Current through the coil
lenz’s law is based on law of conservation of
Energy
On what principle does the transformer workx
Mutual induction
DEFINE ELECTROMAGNETIC INDUCTION
The phenomenon in which electric current is
generated by varying magnetic fields is appropriately called
electromagnetic induction
MAGNETIC FLUX
∅ = B . A = BA cos q
FARADAY 1 ST LAW OF INDUCTION
Faraday’s first law of electromagnetic induction states the following:
Whenever a conductor is placed in a varying magnetic field, an electromotive force is induced. If the conductor circuit is closed, a current is induced, which is called induced current.
FARADAY 22 ND LAW OF INDUCTION
Faraday’s second law of electromagnetic induction states that
The induced emf in a coil is equal to the rate of change of flux linkage.
FORMULA OF FARADAY 2ND LAW
ε= -N dΦ/dv
LENZ LAW
The polarity of induced emf is such that it tends to produce a current which opposes the change in magnetic flux that produced it
MOTIONAL EMF
The emf induced in a conducting rod when it moves in a region of magnetic field is known as motional emf. Motional emf is calculated by using the formula: E=vBl.
The work done in moving the charge from P to Q is
W = qvBl
DEFINE INDUCTANCE
Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it.
DIMENSION OF INDUCTANCE
Inductance is a scalar quantity. It has the dimensions of
[M L2 T–2 A–2]
SI unit of inductance is henry and is denoted by H.
DEFINE MUTUAL INDUCTANCE
A battery and a key are connected to the P-coil, whereas a galvanometer is connected across the S-coil. When there is a change in the current or magnetic flux linked with the two coils, an opposing electromotive force is produced across each coil, and this phenomenon is termed Mutual Inductance.
FORMULA OF MUTUAL INDUCTANCE
∅ = M I
DEFINE SELF INCTANCE
When there is a change in the current or magnetic flux of the coil, an electromotive force is induced. This phenomenon is termed Self Inductance.
FORMULA OF SELF INDCTANCE
∅ = L X I
AC GENERATOR
AN AC GENERTOR CONVERTS MECHANICAL ENERGY INTO ELECTRICAL ENERGY . IT WORKS ON ELCTROMAGNETIC INDUCTION CHANGES
