Question

difference between ac and dc

Answer 1

AC's Advantages over DC

i)   AC is prefered for long distance because of less loss of energy
ii)  AC at any desire voltage can be obtain
iii) AC can be easily converted in DC by using device " Rectifier".

AC's disadvantage over DC

i)  AC cannot be used for Electroplating or electrotyping.
ii) AC gives serious harm to a person when it comes in its contact.

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Answer 2

AC is alternating current where the current changes the direction every second.First it is positive direction which is above the graph and at the other instant it is negative or below the graph.It is used in generators.
It converts mechanical energy to electrical energy.

DC or direct current does not change direction every second.
It is used in motors.It is used to convert electrical energy to mechanical energy.