question_answer

Lenz?s law is expressed by the following formula (here e = induced e.m.f., f = magnetic flux in one turn and N = number of turns)                                                        [MP PET 2002]

A)            \[e=-\varphi \frac{dN}{dt}\] 

B)            \[e=-N\frac{d\varphi }{dt}\]

C)            \[e=-\frac{d}{dt}\left( \frac{\varphi }{N} \right)\]   

D)            \[e=N\frac{d\varphi }{dt}\]