The coil of a large electromagnet has an internal resistance of R = 9.50 Ω. It is in series with a source of EMF of 80.75 V and a switch. The switch is initially open. At t = 0 s, the switch is closed. The graph shows the electric current flowing through the coil as a function of time.
What is the inductance of the coil? Please, notice that the curve passes through at least one grid intersection point.