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.
*************************************************************************
External : "Why does a capacitor block
DC but allow AC To pass through ?
Student: See, a capacitor is like this ---| |--- ,
OK. DC comes straight, like this ----------,
and the capacitor stops it. But AC,goes UP, DOW N, UP DOWN and
jumps right over the capacitor!" .-------------------good one
*************************************************************************
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.
*************************************************************************
Interviewer: How 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.
*************************************************************************