Power dissipation in resistive circuit

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SUMMARY

The discussion centers on calculating power dissipation in a resistive circuit with two identical resistors in series. The total power dissipated by the first circuit is defined as P0, and the second circuit's power, P1, can be expressed as P1 = 0.5P0. The participants emphasize using the formula P = V2/R for both circuits, highlighting that the power ratio is what the problem requires, rather than specific power values. The conversation also stresses the importance of not providing complete solutions to homework questions to encourage learning.

PREREQUISITES
  • Understanding of Ohm's Law (V = IR)
  • Familiarity with power formulas (P = I2R and P = V2/R)
  • Knowledge of series circuits and their properties
  • Basic algebra for manipulating equations
NEXT STEPS
  • Research the implications of adding resistors in series on total resistance and power dissipation
  • Learn about power ratios in electrical circuits and their significance
  • Explore the effects of voltage and resistance on power calculations
  • Study the principles of circuit analysis using Kirchhoff's laws
USEFUL FOR

Students studying electrical engineering, physics enthusiasts, and anyone seeking to understand power dissipation in resistive circuits.

csimon1
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Homework Statement



A single resistor is wired to a battery as shown in the diagram below. (Figure 1) Define the total power dissipated by this circuit as P(subscript 0). Now, a second identical resistor is wired in series with the first resistor as shown in the second diagram to the left (figure 2). What is the power, in terms of P(subscript 0) dissipated by this circuit?

Homework Equations



I am not sure! This problem seems so easy -- I don't think I'm really understanding what they want from me? This is the feedback I got.
The correct answer does not depend on the variables: I, R
So I tried it again...
The correct answer does not depend on the variables: U, t


The Attempt at a Solution



I uploaded the pictures from the question. Can anyone help?
 

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[EDIT] Deleted what I had previously said: "Will your program allow you to input the answer in terms of the variables V and R?"

I think I understand now. The problem statement is asking you for a power ratio. A power divided by a power (not an actual power itself). So once you find the two powers, divide one by the other.
 
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Huh?? Well, my first guess was IsquaredR and then it was U/t...because both those formulas give power. What do you mean a power ratio?
 
The answer not a formula. Don't understand...
 
csimon1 said:
Huh?? Well, my first guess was IsquaredR and then it was U/t...because both those formulas give power. What do you mean a power ratio?

That's fine to start with equations such as

P _0 = (I _0)^2 R.

For the first circuit. But you'll find it easier in this case, if you stick with the given variables (Both circuits are given only in terms of V and R, so you might try to stick with those). Since you already know

V = I _0 R

you'll find it easier to use

<br /> P _0 = \frac{V^2}{R}<br />

Now do the same thing for the second circuit, except call it P _1.

It think your physics program is looking for P_1 / P_0. Give this a try and I think you'll see what I mean.
 
You should also try to put 0.5P0 since by adding one resistor of the same magnitude in series the power should go down by half, since P = V^2/(Sum of R)
 
camm1090 said:
You should also try to put 0.5P0 since by adding one resistor of the same magnitude in series the power should go down by half, since P = V^2/(Sum of R)

Don't give people full solutions to problems in the homework help section, no matter how simple the problem may be.

EDIT: It's against forum rules, and it is also counterproductive for the original poster, who learns nothing and gains nothing from having other people do his/her homework for him/her.
 
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