electromagnetic induction Flashcards
electromagnetic induction
process through which an induced emf is produced in a conductor due to a changing magnetic field
Faraday’s Law
the magnitude of the induced emf in a circuit is directly proportional to the rate of change of magnetic flux in the circuit
Lenz’s Law
the direction of the induced emf, and hence the induced current in a closed circuit, is always such that its magnetic effect opposes the motion or change producing it
transformer
a device that can change high alternating voltage (at low current) to a low alternating voltage (at high current) or vice versa
what is the purpose of using soft iron in a transformer?
soft iron is a soft magnetic material and it is easy to magnetize and demagnetize. hence, magnetic field lines will be concentrated through the soft iron core and there will be better magnetic flux linkage between the two coils which reduces energy loss and increases efficiency
What is the purpose of lamination of soft iron core in a transformer?
to reduce thermal energy loss due to eddy current
how to minimize energy loss through transmission of electrical energy through cables?
Since P=IV, power is transmitted at a high voltage and low current to minimize Ploss=I^2R (without needing to increase thickness of cable beyond reasonable extent)
