A) 1 A
B) 0.5 A
C) 0.2 A
D) 0.1 A
Correct Answer: D
Solution :
The coefficient of self-induction of a coil is numerically equal to the emf (e) induced in the coil when the rate of change of current \[\left( \frac{\Delta \,i}{\Delta \,t} \right)\] in the coil is unity. \[\therefore \] \[L=-\frac{e}{\Delta \,i/\Delta \,t}\] \[\Rightarrow \] \[e=-L\frac{\Delta \,i}{\Delta \,t}\] Given, \[L=60\,mH=60\times {{10}^{-3}}\,H,\] \[\Delta \,i=\left( 1.5-1 \right)A=0.5\,A\] \[\Delta \,t=0.1\,s\] \[\therefore \] \[e=-\frac{60\times {{10}^{-3}}\times 0.5}{0.1}=-0.3\,\,V\] Induced current \[i=\frac{e}{R}=\frac{0.3}{3}=0.1\,\,A\]You need to login to perform this action.
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