$\text{'}$la: The switch is closed in the circuit $($below left$).$ Assume that a current $11$ passes through

RI$,$ a current $12$ passes through $1+2$ and that a current $13$ passes through L$.$ Qualitatively

describe what happens in the circuit. Determine the size of the three currents at time zero

and at time infinity.

b: Use Kirchhoff's rules to determine each current as a function of time. Then verify that

the currents give the correct results at t $=$ O and at t $=$ x$.$ If you cannot solve the system

of three equations $($which you are definitely not required to do$),$ then use my answer for $13$

to determine $11$ and $12.$ What is the effective time constant for this circuit?

c