Here\'s a question from smartPhysics: 5. What is I C,max (open), the current tha
ID: 1320629 • Letter: H
Question
Here's a question from smartPhysics:
5. What is IC,max(open), the current that flows through the capacitor whose magnitude is maximum during the time when the switch is open? A positive value for the current is defined to be in the direction of the arrow shown.
Here's a question from smartPhysics: A circuit is constructed with four resistors, one capacitor, one battery and a switch as shown. The values for the resistors are: R1 = R2 = 42 ohms, R3 = 110 ohms, and R4 = 102 ohms. The capacitance is C = 30 5. What is Ic,max(open), the current that flows through the capacitor whose magnitude is maximum during the time when the switch is open? A positive value for the current is defined to be in the direction of the arrow shown. Mu F and the battery voltage is V = 12 V. The positive terminal of the battery is indicated with a + sign.Explanation / Answer
Charge and Current on the capacitor after the switch has been closed for long time
Q(infinity)=I(infinity)*R3*C =[V/(R1+R3+R4)]*R3*C
Qinfinity=[12/(42+110+102)]*110*(30*10-6)
Qinfinity=1.56*10-4 C
When Switch is open after very long time
Time Constant
T=(R2+R3)C =(42+110)*(30*10-6)
T=4.56*10-3 s
so
IC,max(open) =-Qinfinity/T =-(1.56*10-4)/(4.56*10-3)
Ic,max(open)=-0.0342 A