What is Lenz’s law?
Answer:
A German physicist Heinrich Lenz’s deduced a law which used
to determine the direction of the induced current. Lenz law states that the
direction of the induced current is such that it always opposes the cause
responsible for its production. Michael Faraday discovered electromagnetic
induction. Heinrich Lenz says that induction effect always opposes would flow
in a direction so that it could oppose the flux change.
What is transformer?
Answer:
Transformer
is a device which is used to transform electrical power from one circuit to
another without changing its frequency. The applied alternating voltage is
either increased or decreased with corresponding decrease or increase of
current in the circuit. 
