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.
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 DC. If it gets stuck, it was AC.
Interviewer: How will you reverse direction of an induction motor? Candidate: I will remove the four bolts at the base, turn the motor around, and put back the bolts.
Interviewer: How do you start a synchronous motor?
Candidate: Vrrrrrrrmmmmmmmmmmmmmmmmmmm (in rising pitch)
Interviewer: Stop! Stop!
Candidate: rrrrrrrmmmmmmmmmmmmmmmmmmmm (in falling pitch)
Interviewer: How do you limit surge current within an integrated circuit?
Candidate: By using a miniature circuit breaker.
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!"