Question

In a LR circuit connected to a battery the rate at which energy is stored in the inductor is plotted against time during the growth of current in the circuit. Which of the following best represents the resulting curve?

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

Answer 2

U = $\frac{1}{2}$LI₂

Rate = $\frac{dU}{dt}$ = LI $\left( \frac{dI}{dt} \right)$

At t = 0 , I = 0

\ Rate = 0

At t = , I = I₀ but $\frac{dI}{dt}$ = 0, therefore, rate = 0