A time varying voltage V= 2t (Volt) is applied across and ideal inductor of inductance L =2H as shown in Fig. Then (assume current to be zero at t =0)

Options

A. Current versus time graph is a parabola
B. energy stored in magnetic field at `t=2s is 4J`.
C. Potential energy at time `t=1s` in magnetic field is increasing at a rate of `1J//s`
D. energy stored in magnetic field is zero all the time.

Answer

A, B, C

Explanation

`V=2t implies L(di//dt)=2t`
`2(di//dt)=2T implies di//dt=t`
`i=t^(2)//2 implies i-t "graph is parabola"`
at `t=2s, i=2A`
`U=(1//2)Li^(2)=4J`
`dU//dt = Li(di//dt)=t^(3)=1 J//s`.