Saved Bookmarks
| 1. |
Obtain an expression for energy stored in an inductor connected to a source voltage. |
|
Answer» Solution :When a current grows through an inductor, the induced emf opposite its growth and as such it has to do some work . LET the current flowing through the circuit at any instant t be i. The rate of growth of current at the time `=(di)/(dt)` The induced emf set up in the inductor `E=L (di)/(dt)` The work done by the current in increasing from zero to its maximum value `I,W int_(0)^(1) dW`. But dW = Ei dt, Note : power = `("work")/("time")` i.e., dW = `L((di)/(dt))IDT= Li di`. Hence `W=int_(0)^(1)Lidi=L((i^2)/(2))_0^1 or W=1/2LI^2`. This amount of work done is stored in the form ofmagnetic energy . We note that the SELF INDUCTANCE is the electrical inertia which opposes the growth or decay of current in the circuit. |
|