The magnetic field of a coil with an inductance of 0.1 Gi has an energy of 0.8 J. What is the current in the coil?

As we know from the school physics curriculum, the energy of a magnetic field can be calculated by using the following formula:

W = L * I² / 2, where L is the inductance of the coil, and I is, respectively, the current in it.

Let us determine what value the current in the coil will equal if, from the condition of our problem, we know for sure that its magnetic field has an inductance of 0.1 H and an energy of 0.8 J:

W = L * I² / 2;

I = √ (2W / L);

√ (2 * 0.8 / 0.1) = √16 = 4.

Answer: The current strength is 4 A.