Question:medium

Two resistors, 4Ω and 6Ω, are connected in parallel, and this combination is connected in series with a 2Ω resistor to a 12V battery. What is the total power dissipated?

Show Hint

For circuits with resistors in series and parallel, first find the equivalent resistance of the parallel combination, then combine it with the series resistors to calculate the total resistance and the power dissipated.
Updated On: Jan 13, 2026
  • 32.7 W
  • 28.8 W
  • 24.0 W
  • 36.0 W
Show Solution

The Correct Option is A

Solution and Explanation

The equivalent resistance of the parallel combination of the 4Ω and 6Ω resistors is calculated as follows: \[ \frac{1}{R_{\text{eq}}} = \frac{1}{4} + \frac{1}{6} = \frac{3}{12} + \frac{2}{12} = \frac{5}{12} \] \[ R_{\text{eq}} = \frac{12}{5} = 2.4 \, \Omega \] This equivalent resistance is then in series with the 2Ω resistor, yielding a total circuit resistance: \[ R_{\text{total}} = R_{\text{eq}} + 2 = 2.4 + 2 = 4.4 \, \Omega \] Ohm's law is applied to determine the total current in the circuit: \[ I = \frac{V}{R_{\text{total}}} = \frac{12}{4.4} = 2.73 \, \text{A} \] The total power dissipated is then calculated using the formula \( P = I^2 R \): \[ P = (2.73)^2 \times 4.4 = 7.46 \times 4.4 = 32.7 \, \text{W} \] The total power dissipated by the circuit is 32.7 W.
Was this answer helpful?
2