3. When the strength of
the current in one of the two
adjacent coil changes, a
change take place in the
magnetic field around . As a
result of this an emf is induced
in the second coil . This
phenomenon is mutual
induction .
The coil which
supplied electric current is the
primary and the other in which
emf is induced is the secondary
5. Transformer is a device that employs the
principle of mutual induction.
It is used in tape recorder, radio etc,.
Transformer are of two type:
(a)Step up transformer
(b)Step down transformer
7. Thick wire is used to wind the primary coil.
Primary coil contains less number of turns.
Secondary contains more number of coil.
Thin wire is used in the secondary.
9. Thin wire is used to wind the primary coil.
Primary contain more number of turns.
Secondary contain s less number of turns.
Thick wire is used in the secondary coil.
11. The relation between the number of turns of the coil of
a transformer and the induced emf can be
Mathematically written as,
Vs/Vp=Ip/Is=Ns/Np
Vs=Voltage in the secondary coil
Is=Secondary current
Vp=Voltage in the primary coil
Ip=the primary current
Ns=Number of turns in the secondary coil
Np=Number of turns in the primary coil