5W       t=1          5W            5W           A      B                       +  VR – 100 u(1-t)V                       0

5W       t=1          5W            5W

          A      B                       +  V_R –

100 u(1-t)V                       0.8 V_R

       V_c(t)  3F               2W          60 u(t-1)v

At t=1; the switch changes its position from A to B.

1. Find the value for V_c (1⁺).

2. Find the time constant (t) of the following first order circuit after the switch is moved from A to B (i.e., > 1)?

3. Find the expression of v_c (1^-) for t > 1 s.

4. What is the magnitude of the change in energy (in KJ) in the capacitor from t = 1 s to t = ¥?