A 2.00-nF capacitor with an initial charge of 5.46 C is discharged through a 1.3

Question

A 2.00-nF capacitor with an initial charge of 5.46 C is discharged through a 1.37-k resistor. (a) Calculate the current in the resistor 9.00 s after the resistor is connected across the terminals of the capacitor. (A positive current will correspond to a charging capacitor and a negative current will correspond to a discharging capacitor. Let the math do the work for you!) mA (b) What charge remains on the capacitor after 8.00 s? (c) What is the (magnitude of the) maximum current in the resistor?

Explanation / Answer

a) We know that, Q = CV

So, V = Q/C

Initial V = (5.46*10^-6) / (2*10^-9) = 2730 V

Time constant = RC = 1370 * 2*10^-9 = 2.74 us

Initial current = V/R = 2730 / 1370 = 2 A

Current afer 9 us = 2e^(-9 / 2.74) = 0.075 A

b) Q = 5.46*10^-6 * e^( -8/2.74)

= 0.294 uC

c) The max current = initial current = 2 A (see above - needed to work out part a))

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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