3. (a) Assign the polarity to the resistors in the circuit and (b) using Kirchhoff's Laws, determine the currents in the following circuit 4. An RC circuit has been open for a long period of time. At t = 0 the circuit is closed connecting all its components. If R = 20 kQ, C = 30 pF, and V = 20 V. Determine: (a) The constant t = RC (b) The charge on the capacitor when t = t