Consider the circuit shown in the figure, where R 1 = 27 ? and R 2 = 4.8 ?. (a)
ID: 1373672 • Letter: C
Question
Consider the circuit shown in the figure, where R1 = 27 ? and R2 = 4.8 ?.
(a) Is the current flowing through the battery immediately after the switch is closed greater than, less than, or the same as the current flowing through the battery long after the switch is closed?
lessersame greater
(b) Find the current flowing through the battery immediately after the switch is closed.
(c) Find the current in the battery long after the switch is closed.
Explanation / Answer
a) Immediately after the switch is closed , capacitor is uncharged , so it acts as a short circuit. Current flowing through R2 = 0 . Maximum current flows through the battery
Long time after the switch is closed , capacitor is completely charged. It acts as if it is no there. It acts as an open circuit. So the circuit flowing through the battery is minimum.
Answer : greater
b) current flowing through the battery immediately after the switch is closed = V / R1 = 9/27 = 0.33 A
c) current in the battery long after the switch is closed = V /(R1+R2) = 9/(27+4.8) = 0.283 A