I would be grateful if someone could explain to me how the voltage varies across the inductor when the switch is opened (starting from the closed position, steady state condition).

I think I can see what the current will do: decrease exponentially from 15A to 0. But in what direction will the current flow? Towards the resistor or towards the battery? (Please state what convention for current direction you are using).

The voltage drop across the inductor is initially zero. When the switch is opened, how does the voltage vary with time at the following four different points:

a) the point between the battery and the switch

b) the point between the switch and the resistor

c) the point between the resistor and the inductor

d) the point between the inductor and the battery

Any help will be very much appreciated. Thank you!

Miguel