Mastering Physics Solutions: Power Dissipation in Resistive Circuit Conceptual Question

Power Dissipation in Resistive Circuit Conceptual Question

Part A = 0.5P0
Part B = 2P0

Solutions Below:

A single resistor is wired to a battery as shown in the diagram below. (Intro 1 figure) Define the total power dissipated by this circuit as P0.

Mastering Physics Solutions: Power Dissipation in Resistive Circuit Conceptual Question

Part A

Now, a second identical resistor is wired in series with the first resistor as shown in the second diagram to the left (Intro 2 figure).

Mastering Physics Solutions: Power Dissipation in Resistive Circuit Conceptual Question

What is the power, in terms of P0, dissipated by this circuit?
Express your answer in terms of P0.

Power is given by the formula W = V2/R. If the amount of resistance doubles, then the power will be halved.

0.5P0

Part B

The second resistor is now removed from the circuit and rewired in parallel with the original resistor as shown in the schematic to the left (Intro 3 figure)

Mastering Physics Solutions: Power Dissipation in Resistive Circuit Conceptual Question

What is the power, in terms of P0, dissipated by this circuit?
Express your answer in terms of P0.

With the two resistors in parallel, their combined resistance is given by ((1 / R1) + (1 / R2))^1. This will halve the resistance, and power will double.

2P0

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