A) \[3.2\,\,\pi \mu V\]
B) \[4.8\,\,\pi \mu V\]
C) \[0.8\,\,\pi \mu V\]
D) \[1.6\,\,\pi \mu V\]
Correct Answer: A
Solution :
Key Idea According to Faraday's second law of electromagnetic induction the induced emf is given by rate of change of magnetic flux linked with the circuit. |
Here, \[B=0.04\,T\] |
and \[\frac{-\,dr}{dt}=2\,mm{{s}^{-1}}\] |
Induced emf, \[e=\frac{-d\phi }{dt}=\frac{-BdA}{dt}=-B\frac{d(\pi {{r}^{2}})}{dt}\] |
\[=-B\pi 2r\,\frac{dr}{dt}\] |
Now, if \[r=2\,cm\] |
\[e=-0.04\,\times \,\pi \,\times 2\times 2\times {{10}^{-2}}\times 2\times {{10}^{-3}}\] |
\[=3.2\,\pi \mu V\] |
You need to login to perform this action.
You will be redirected in
3 sec