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(a) What is the charge on the upper plate of the capacitor just as the switch th

ID: 1322090 • Letter: #

Question

(a) What is the charge on the upper plate of the capacitor just as the switch throw is moved to contact b?
C

(b) What is the current just after the switch throw is rotated to contact b?
A

(c) What is the time constant of this circuit?
ms

(d) How much charge is on the upper plate of the capacitor 7.00 ms after the switch throw is rotated to contact b?
C

For the circuit shown in the figure below, C = 4.00 F, (a) What is the charge on the upper plate of the capacitor just as the switch throw is moved to contact b? (b) What is the current just after the switch throw is rotated to contact b? A (c) What is the time constant of this circuit? ms (d) How much charge is on the upper plate of the capacitor 7.00 ms after the switch throw is rotated to contact b? C = 80 V, and R = 600 ?. After having been at contact a for a long time, the switch throw is rotated to contact b.

Explanation / Answer

a)

Q = C*V = 4 uF * 80V = 320 uC

b)

I = V/R = 80/600 = 0.133 A

c)

T = R*C = 600*4*10^-6 = 2.40 ms

d)

Q(t) = Q*e^-t/T

= 600 *e^(-7/2.4)

= 32.47 uC