• # question_answer 11) In a coil rate of change of area is  $5\text{ }{{m}^{2}}/\text{ }millisecond$ and current becomes 1 amp from 2 amp in $2\,\,\times \,\,{{10}^{-}}^{3}$ sec. If magnitude of field is 1 tesla then self-inductance of the coil is A) 2 H                              B) 5 HC) 20 H                D) 10 H

$e=L\frac{dI}{dt}\,\,\Rightarrow \,\,e=B\frac{dA}{dt}$ $B\frac{dA}{dt}=L\frac{dI}{dt}$