Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

The values of the components in a simple series RC circuit containing a switch a

ID: 1875013 • Letter: T

Question

The values of the components in a simple series RC circuit containing a switch and an initially uncharged capacitor (see figure below) are C = 1.40 µF, R = 1.90 M, and e m f = 10.0 V.

(a) the charge on the capacitor...

...a long time after the switch is closed q = µC

...1.9 s after the switch is closed q = µC

(b) the current in the resistor...

...immediately after the switch is closed I0 = µA

...1.9 s after the switch is closed I = µA

... a long time after the switch is closed I = µA

(c) The rate at which energy, 1.9 s after the switch is closed, is...

...being dissipated in the resistor Presistor = µW

...being stored in the capacitor Pcapacitor = µW

...being delivered by the battery Pbattery = µW

C=

Explanation / Answer

a)

T = time constant = RC = (1.90 x 106) (1.40 x 10-6) = 2.66 sec

q = charge stored by capacitor after long time = CV = 1.40 x 10 = 14 µC

q = charge at time 1.9 sec = q (1 - e-t/T) = (14) (1 - e-1.9/2.66) = 7.15 µC

b)

Io = V/R = 10/(1.9 x 106) = 5.3 x 10-6 A

I = ( Io/T) e-t/T = ((5.3 x 10-6)/2.66) e-1.9/2.66 = 9.8 x 10-7 A

at long time

I = 0

c)

in resistor , P = I2 R = (9.8 x 10-7)2 (1.9 x 106) = 3.7 Watt