Number 35 PLEASE Consider a series RC circuit for which R = 1.0 MOhm. C = 5.0 mu

Question

Number 35 PLEASE

Consider a series RC circuit for which R = 1.0 MOhm. C = 5.0 muF, and epsilon = 30 V as in Figure P18.33. Find the charge on the capacitor 10 s after the switch is closed. A charged capacitor is connected to a resistor and a switch as in Figure P18.35. The circuit has a time constant of 1.50 s. Soon after the switch is closed, the charge on the capacitor is75.0% of its initial charge. (a) Find the time interval required for the capacitor to reah this charge. (b) If R = 250 kOhm, what is the value of C? Figure P18.35

Explanation / Answer

Part A)

The formula for the charge on a capacitor as a function of time is

q = Q(1-e-t/) where Q is the maximum value of the charge on the capactior

By substitution

.75Q = Q(1 - e-t/) Note Q cancels

Solve for t

e-t/ = 1-.75

-t/ = ln(.25)

t = -ln(.25) (1.5)

t = 2.08 sec

Part B)

= RC

C = /R

C = 1.5/250 X 103

C = 6 X 10-6 F   or 6F

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

---

---

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