A circuit is constructed with four resistors, one capacitor, one battery and a switch as shown. The values for the resistors are: R1 = R2 = 74 Ω, R3 = 63 Ω and R4 = 60 Ω. The capacitance is C = 46 μF and the battery voltage is V = 24 V.

What is I1(∞), the magnitude of the current that flows through the resistor R1 a very long time after the switch has been closed?

Question

A circuit is constructed with four resistors, one capacitor, one battery and a switch as shown. The values for the resistors are: R1 = R2 = 74 Ω, R3 = 63 Ω and R4 = 60 Ω. The capacitance is C = 46 μF and the battery voltage is V = 24 V.     

What is I1(∞), the magnitude of the current that flows through the resistor R1 a very long time after the switch has been closed?

anonymous · Answer

how can we help you if there is no circuit shown? how resistors are connected with respect to capacitor and source voltage?

anonymous · Answer

attachment

radar · Answer

practically  after 5 time constants the capacitor will charge up to its "final" voltage of approximately 12.1328 volts.  So the circuit can be considered a series circuit with a resultant current of 88.56 milli-amps.  that would also be the current thru R1.

anonymous · Answer

Thank you!!

radar · Answer

Initially, there will be a increase in current when switch is closed, this is to accomodate the charging current for the capacitor.  The capacitor will charge up to its final value and since we are dealing with DC the steady state of 88.56 ma will continue until the switch is opened, then the capacitor will discharge thru R2 and R3 until it settles to 0 volts (5 time constants again but will be slightly different than the charging time constant as R1 and R4 no longer in the path.)

theeric · Answer

That extra information is useful to think about, thanks!