Answer
0.593 H
Work Step by Step
Use equation 21-9 to find the self-inductance. The current is increasing, and the emf is negative.
$$\epsilon=-L\frac{\Delta I}{\Delta t}$$
$$L =-\epsilon \frac{\Delta t}{\Delta I}$$
$$L =-(-2.50V) \frac{0.0140s}{0.0310A-(-0.0280A)}=0.593H$$