Power Dissipated for 2 different circuits

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Homework Help Overview

The discussion revolves around comparing power dissipation in two different electrical circuits involving resistors R1 and R2. The original poster presents equations for current through R2 in both circuits and poses questions about the conditions under which power dissipation varies.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to equate the currents through R2 in both circuits to find a ratio of R1 to R2. They express uncertainty about manipulating the equations due to a lack of recent physics or math experience. They also explore conditions for power dissipation comparisons by substituting values.

Discussion Status

Participants are engaging with the problem, with some requesting additional information such as diagrams. The original poster is seeking confirmation on their findings after simplifying the equations, indicating an ongoing exploration of the topic.

Contextual Notes

The original poster mentions a lack of recent coursework in physics or math, which may affect their confidence in solving the problem. There is also a focus on identifying the most restrictive condition for power dissipation comparisons.

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Part A:
For what ratio of R1 and R2 would power dissipated by the resistor of resistance R2 be the same for circuit A and circuit B?

current for R2 of circuit A is (2EMF)/(2R1+R2)
current for R2 of circuit B is (EMF)/[(R1^2/2R1) + R2)

Part B:
Under which of the following conditions would power dissipated by the resistance in circuit A be bigger than that of circuit B? Choose the most restrictive answer.
R2<R1
R2>R1
R2<2R1
R2<.5R1

Equations used:
P = IV = I^2 x R = V^2 /R

Attempt:
I understand since R and P is same for both i only have to make the 2 currents equal.
(2EMF)/(2R1+R2) = (EMF)/[(R1^2/2R1) + R2)
I haven't taken physics or math class in 2 years so I'm kinda unsure on how to continue.
Since EMF is constant can I just remove it?

For part B just by plugging in numbers R2>R1 works but I am not certain
 
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Diagram please.
 
totally forgot but here it is

4km5h.jpg
 
deleting my post
 
if i can take out EMF and make R2 = 1 i come out with 4 as my answer. can anyone confirm?
 

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