Question

(Only need d, e, and f)

A resistor R = 12 MΩis connected in series with a capacitor C = .7 μF and a battery V = 12 volts.

a) What is the time constant of this circuit?

b) How many seconds will it take for the voltage across the capacitor to equal 10 volts?

c) How many seconds will it take for the current to drop to 20% of its maximum value?

d) After 30 seconds, what are the voltages across the capacitor and resistor, the charge across the capacitor, and the current in the circuit?

e) How many seconds will it take for the voltage of the capacitor to be 3 times larger than the voltage of resistor?

f) From t = 0 to t = 6 seconds, what is the total energy delivered by the battery, the total energy stored in the capacitor, the total energy lost as heat in the resistor? At t = 6 seconds, what is the power supplied by the battery and the power dissipated as heat in the resistor?

Answers should be:

d.) V_R = .34 volts, V_C = 11.66 volts, Q = 8.16 μC, I = 28.1 namps

e.) 11.64 seconds

f.) Ubattery = 51.45 μJoules, Ucapacitor = 13.13 μJoules, Uresistor = 38.32 μJoules

Pbattery = 5.87 μwatts, Presistor = 2.88 μwatts

Answer 1