---
title: "A circuit contains an ideal DC power supply with a potential difference of \\(\\Delta V = 12\\text{ V}\\) connected in series with two ohmic resistors, \\(R_1 = 4.0\\text{ }\\Omega\\) and \\(R_2 = 8.0\\text{ }\\Omega\\), as shown in the diagram. What are the equivalent resistance of the circuit and the rate of energy dissipated as thermal energy by resistor \\(R_2\\)?"
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url: "https://nerd-notes.com/ubq/117418/"
date_modified: "2026-08-04T06:52:05+00:00"
---

# A circuit contains an ideal DC power supply with a potential difference of \(\Delta V = 12\text{ V}\) connected in series with two ohmic resistors, \(R_1 = 4.0\text{ }\Omega\) and \(R_2 = 8.0\text{ }\Omega\), as shown in the diagram. What are the equivalent resistance of the circuit and the rate of energy dissipated as thermal energy by resistor \(R_2\)?

A circuit contains an ideal DC power supply with a potential difference of \(\Delta V = 12\text{ V}\) connected in series with two ohmic resistors, \(R_1 = 4.0\text{ }\Omega\) and \(R_2 = 8.0\text{ }\Omega\), as shown in the diagram. What are the equivalent resistance of the circuit and the rate of energy dissipated as thermal energy by resistor \(R_2\)?

![A simple schematic circuit diagram oriented horizontally. On the left vertical side, an ideal DC battery is oriented with its longer positive terminal on top and shorter negative terminal on the bottom, labeled '\Delta V = 12\text{ V}'. Wires extend from the top and bottom battery terminals to form a closed rectangular loop. The top horizontal wire segment contains a single resistor labeled 'R_1 = 4.0 \Omega'. The right vertical wire segment contains a second resistor labeled 'R_2 = 8.0 \Omega'. No other labels, lines, arrows, or text appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785826325-TT2sPx.jpg)

- **A.** \(2.7\text{ }\Omega\) equivalent resistance and \(18\text{ W}\) power dissipated
- **B.** \(12\text{ }\Omega\) equivalent resistance and \(4.0\text{ W}\) power dissipated
- **C.** \(12\text{ }\Omega\) equivalent resistance and \(8.0\text{ W}\) power dissipated
- **D.** \(12\text{ }\Omega\) equivalent resistance and \(18\text{ W}\) power dissipated

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/117418/*