Stae one main difference between A.C and D.C. Why A.C is preferred over D.C for long range transmission of electric power ? Name one source each of D.C and A.C ?

Explanation

Difference between A.C and D.C : The Alternating Current (A.C) reverses its direction periodically. Whereas the direct current (D.C) always flows in one direction. A.C is preferred over D.C because it can be transmitted over long distance without much loss of energy.
D.C source : Battery, A.C source : A.C generator