(a)Lifts; Conveyors;
Industrial air conditioners;
Industrial drives.
(b)(i) Turns ratio = Ns / Np = Vs/ Vp
= 12 / 240 = 1 //20
Np : Ns = 20:1
(ii) Np = (Ns * Vp) / Vs
= (100 * 240) / 12 = 2000 turns
(iii) Is / Ip = Vs / Vp
Ip = (12 * 12) / 240 = 0.1A
This question was on electrical machines (A.C.). The question was popular. Many candidates got turns ratio, primary turns and current correctly but a few did not which may be due to inadequate preparation and insufficient practice.