Question

The circuit pictured below shows a battery, two resistors, an uncharged capacitor in parallel with one of the resistors, and a switch, which can be opened (as pictured) or closed.
After the switch has been closed for a very long time (when the current reaches "equilibrium"), what is the current through the $12.0ohm$ resistor?

• A. $0.75A$
• B. $1.50A$
• C. $0.50A$
• D. $0.67A$
• E. No current flows through the $12.0ohm$ resistor $\left(0A\right)$

Answer 1

Answer: (C)

$0.50A$

After the switch has been closed for a long time, current through the capacitor is zero.

Thus total resistance of the circuit $R=12.0+6.0=18.0$ ohms

$\therefore$ Current through 12.0 ohm resistor $I=\frac{V}{R}=\frac{9.0}{18.0}=0.50$ $A$