**Unit 3**

1270 PRACTICE EXAM

1. (30 points)

After
being closed for a long time, the switch is __opened__ at t = 0.

a. Write a numerical expression for i(t), t > 0.

b. Calculate the energy stored in the capacitor at t = 0+.

c. Calculate the energy stored in the capacitor as t -> °.

2. (25 points)

After
being closed for a long time, the switch is __opened__ at t = 0.

a. Write an expression for v1(t), t > 0.

b. Make one consistency check (other than units) on your answer.

3. (20 points)

a. Calculate the value of RL that would absorb maximum power.

b. Calculate that value of maximum power RL could absorb.

4. (25 points)

Using superposition, derive an expression for v3 that contains no circuit quantities other than is, vs, R1, R2, and .