Consider the circuit shown for which R 1 =3.0 M?, R 2 =0.9 M?, R 3 =3.9 M?, R 4
ID: 1323096 • Letter: C
Question
Consider the circuit shown for which R1=3.0 M?, R2=0.9 M?, R3=3.9 M?, R4=4.8 M?, C=5.4 ?F,and E=19.0 V. For charging, we open S2 and close S1. For discharge, after a full charge, we open S1 then close S2.
a) What is the charge time constant for the circuit? Answer in units of seconds.
b) What is the discharge time constant for the circuit? Answer in units of seconds.
After fully discharging the circuit, we close S2 and then close S1. The capacitor will charge.
c) What is in micro-amps the current through R2 once the capacitor is fully charged?
d) What is in micro-amps the current through R3 once the capacitor is fully charged
Consider the circuit shown for which R1=3.0 M?, R2=0.9 M?, R3=3.9 M?, R4=4.8 M?, C=5.4 ?F,and E=19.0 V. For charging, we open S2 and close S1. For discharge, after a full charge, we open S1 then close S2. a) What is the charge time constant for the circuit? Answer in units of seconds. b) What is the discharge time constant for the circuit? Answer in units of seconds. After fully discharging the circuit, we close S2 and then close S1. The capacitor will charge. c) What is in micro - amps the current through R2 once the capacitor is fully charged? d) What is in micro - amps the current through R3 once the capacitor is fully chargedExplanation / Answer
a)charging time constant = (R1 +R2 +R4 )*C = (3+0.9+4.8) *106 *5.4 *10-6 = 46.84 seconds (ans)
b) discharging time constant =(R2 +R3)*C = (0.9+3.9) *106 * 5.4 *10-6 = 25.92 seconds (ans)
c) currrent through R2 = 0 (capacitor is open circuit.
d) current through R3 = 19/(R2+R3) = 19/4.8 = 3.958 *10-6 A = 0.003958 mA (ans)
-------------NOTE-----------
the above eqn is solved assuming the capacitance is in muF
If it is in nF , the ans for a ) 0.0469 seconds
for b) 0.0259 seconds