State the energy stored in an inductor.

A \(0.20\,\mathrm{H}\) inductor carries \(3.0\,\mathrm{A}\). Find the stored energy.

How does stored magnetic energy change if current doubles?

A \(5.0\,\mathrm{mH}\) inductor carries \(2.0\,\mathrm{A}\). Find the stored energy.

An inductor stores \(2.0\,\mathrm{J}\) at \(4.0\,\mathrm{A}\). Find \(L\).

An inductor with \(L=0.80\,\mathrm{H}\) stores \(10\,\mathrm{J}\). Find the current.

State the magnetic energy density in a medium of permeability \(\mu\).

Find the vacuum magnetic energy density for \(B=0.10\,\mathrm{T}\).

Why is magnetic energy always nonnegative in the ideal inductor formula?

Derive \(U_B=\frac12LI^2\) from power into an inductor.

An inductor current increases linearly from \(0\) to \(6.0\,\mathrm{A}\). If \(L=0.30\,\mathrm{H}\), how much energy is stored at the end?

A \(0.50\,\mathrm{H}\) inductor current decreases from \(4.0\,\mathrm{A}\) to \(1.0\,\mathrm{A}\). How much magnetic energy is released?

Why does an inductor behave like an energy-storage element rather than an energy-dissipating element?

A long solenoid has field \(0.050\,\mathrm{T}\) in air and volume \(4.0\times10^{-4}\,\mathrm{m^3}\). Estimate the total magnetic energy.

Show that \(1\,\mathrm{H\,A^2}\) has units of joules.

A \(2.0\,\mathrm{H}\) inductor carries current \(I(t)=3.0t\) for \(t\) in seconds. Find stored energy at \(t=2.0\,\mathrm{s}\).

At one instant an inductor has \(I=5.0\,\mathrm{A}\) and \(dI/dt=-2.0\,\mathrm{A\,s^{-1}}\), with \(L=0.40\,\mathrm{H}\). Find the rate of change of stored energy.

Why does a collapsing inductor current sometimes produce a large voltage?

Compare capacitor energy and inductor energy in terms of the circuit variable being squared.

Explain why the field energy density \(u_B=B^2/(2\mu)\) and circuit energy \(U_B=\frac12LI^2\) are consistent for a solenoid.