Question

Physics- Electricity problem

Answer 1

After a long time, V(capacitor)=V(battery) therefore the current through the capacitor must be zero. The system is now composed of two parallel circuits.The current through resistors with resitance 1 and 4 ohms and the 8 and the 2ohms are 2 and 1 amps.
The voltage across the 1 ohm resistor is 2 V and the voltage on the 8 ohm resistor is 8V
The voltage across the capacitor: 8-2=6V
Once we remove the battery in which path is the capacitor going to discharge.

Answer 2

Correct so far :))

Answer 3

Once the battery is removed, the capacitor will see parallel combination of two series resistors (8 ohm + 1 ohm ) || (4 ohm + 2 ohm), more current will flow through the less series resistance combination, but it is not necessary here to know.
After simplification of circuit to one cap and one resistor, it should be easy to find the time after which cap will be 10% charged. Could you do now?

Answer 4

Calculate the RC (time constant) Using the value of the equivalent resistor and the capacitor.
The initial voltage of 6 volts discharging to .6 volts. determine the length of time for that to occur. Use the equation provided in your study material.