A student performing the experiment concerning capacitors, resistors, and RC cir

Question

A student performing the experiment concerning capacitors, resistors, and RC circuits is given a resistor and a capacitor. A power supply set to 5.00 volts is connected across the RC circuit and left until tire capacitor is fully charged. At a time of 1.75 seconds after charging starts, the potential difference across the capacitor is 3.00 volts, What is the time constant X for the RC combination? If the capacitor has a capacitance of 0.200 F, what is the resistance of the resistor? What is the current through the resistor at t = 1.75 seconds?

Explanation / Answer

Vo = 5 V , V = 3V , t =1.75 s

(a) for charging RC circuit

Q = Qo (1-e^-t/T)

V =, Vo (1-e^-t/T)

3 = 5(1-e(-1.75/T)

1.75/T = ln(2.5)

time constant T = 1.91 s

(b) C =0.2 F
time constant T =RC

R*0.2 = 1.91

R = 9.55 ohms

(c) i = dQ/dt

i = io (e^-t/RC)

io = Vo/R = 5/9.55

i = (5/9.55) (e^-(1.75/1.91))

i =0.21 A

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.