Consider the circuit shown in the figure. The battery has emf ε = 25 volts and negligible internal resistance. The inductance is L = 0.80 H and the resistances are R1 = 12 Ω and R2 = 9.0 Ω. Initially the switch S is open and no currents flow. Then the switch is closed. 
(a) What is the current in the resistor R1 just after the switch is closed?
(b) After leaving the switch closed for a very long time, it is opened again. Just after it is opened, what is the current in R1?
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