question_answer

In a coil of resistance\[10\Omega .\], the induced current developed by changing magnetic flux through it, is shown in figure as a function of time. The magnitude of change in flux through the coil is:

A) 8                     

B) 2       

C) 6                     

D) 4

Correct Answer: B

Solution :

Charge included in coil q = (area under I - t graph) \[\,q=\frac{1}{2}\times 4\times 0.1=0.2\] \[\operatorname{Emf}\phi =\frac{d\phi }{d\phi }\] \[\operatorname{I}.R=\frac{d\phi }{d\phi }\] \[d\phi =\operatorname{Idt}.R\] \[\phi =\operatorname{Q}\operatorname{R}\] \[\phi =0.2\times 10\] \[\phi =2\operatorname{Wb}\]