Emf Flashcards
If two force in a currentc carrying conductor move in the same direction
The force is attractive
The device for converting electrical energy to mechanical energy
Electric motor
The galvanometer works on the principle of
A current carrying conductor
To increase the sensitivity of the galvanometer
Field is made stronger,number of turns increased,area of coil is increased,springs are made thinner
Who discovered em.i
Micheal Faraday
The induced emf depends in
Speed of the magnet/coil,number of turns,the presence of a soft iron core
Faradays law is based on the concept that
Change in lines of force is proportional to rate s directly proportional to emf induced,the strength of the emf also proportional to the flux
The magnetic flux depends on
(i)Magnetic field strength,number of turns,Area of each turn
Generators are divided into 2
Ac generator,And D.C generator
Ac current can be measured by
Hot wite ammeter,M.V.C galvanometer,M.I.Ammeter
Ac can be made to produced dc by replacing
The two slips rings with a single split ring commutator
The split ring is
A current reverser
Mutual inductance is
Flow of inductance in a coil due to Ac
Eddy currents reduce efficiency cause they
They consume power from the primary
hysteresis loss
Wasted energy due to reversing the magnetization ofthe core
Energy is lost in also
Leakage Of magnetic flux
Heat is lost in a transformer by
Eddy current(solved by lamination),hysteresis loss,I^2R,Leakage of Magnetic flux
Hysteresis loss is reduced by
The use of soft iron core
Heat loss can be reduced by heat loss
Thick wires or low resistance coils
Leakage is reduced by
Special coils of winding
High tension transmission is known as
High voltage and low current
Ac is preferred to DC in high tension transmission because
Ac can easily be stepped up while dc Volatage cannot
Induction coil is used
In motor car and xray tubes
____ changes the rapid speed in the
Make and break device
