1.Interviewer:Why is a thicker conductor necessary to carry a current in A.C.as compared to D.C. ?
Candidate: An AC current goes up and down (drawing a sinusoid) and requires more space inside the wire, so the wire has to be thicker.
2.Interviewer:Why does a capacitor block DC but allow AC To pass through ?
Candidate:See, a capacitor is like this ---| |--- , OK. DC comes straight, like this ----------, and the capacitor stops it. But AC,goes UP, DOWN, UP DOWN and jumps right over the capacitor!-------------------.
3.Interviewer: How will you tell if that wall outlet carries AC or DC?
Candidate: I will put my finger in. If it is pushed away, it is AC. If it gets stuck, it was DC.
4.Interviewer: H! ow will you reverse direction of an Induction motor?
Candidate: I will remove the four bolts at the x-ud, turn the motor around, and put back the bolts.
5.Interviewer: How do you start a synchronous motor?
Candidate: Vrrrrrrrmmmmmmmmmmmmmmmmmmm (in rising pitch)
6.Interviewer: Stop! Stop!
Candidate: rrrrrrrmmmmmmmmmmmmmmmmmmmm (in falling pitch)
7.Interviewer:What is a step-up transformer?
Candidate:A transformer that is put on top of electric poles.
8.Interviewer (smiling):And then what is a step-down transformer?Candidate:hesitantly):Uh - A transformer that is put in the x-udment or in a pit?