Answer by BE students

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  (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!"

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:  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.      

Interviewer:  How do you start a synchronous motor?  
Candidate:  Vrrrrrrrmmmmmmmmmmmmmmmmmmm (in rising pitch)  
Interviewer: Stop! Stop!  
Candidate:  rrrrrrrmmmmmmmmmmmmmmmmmmmm (in falling pitch)  

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 transformer that is put in the x-udment 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!"