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.
Examiner (to student): 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, DOWN, Up DOWN
and jumps right over the capacitor!"
Examiner: "What is a step-up
transformer?"
Student: "A transformer that is put on top of electric poles."
Examiner (smiling): "And then what is a step-down transformer?"
Student (hesitantly): "Uh -- A transfomer that is put in the
basement or in a pit?"
Examiner (pouncing): "Then what do you call a transformer that is
installed on the ground?" (Student knows he is caught -- can't answer)
Examiner (impatiently): "Well?"
Student (triumphantly): "A stepless transformer, sir!" |
