Calculate New Power when adding a Resistor

In summary, the conversation discusses a problem involving a resistor connected to a battery and the rate at which electrical energy is dissipated. The problem is solved by first finding the current, then the equivalent resistance when a second resistor is added in series. The conversation also mentions the suggestion to calculate the battery voltage and the realization that the current remains constant in series.
  • #1
Apaullo13
2
0
As this is my first post please feel free to correct me if I am posting this is the wrong section or on improper etiquette in general. I'm having a bit of trouble with what should be a pretty simple problem.

Homework Statement


A resistor R1 = 23Ω is connected to a battery that has negligible internal resistance and electrical energy is dissipated by at a rate of 44W.

If a second resistor R2 = 20Ω is connected in series with R1 , what is the total rate at which electrical energy is dissipated by the two resistors?

Homework Equations


P=VI=I2R, V=IR

The Attempt at a Solution



I first solved for the current I by using the equation P=I2R using my R1. I found the current to be I=1.38A.

From there I found the equivalent resistance by adding my resistances as they are in series to get an equivalent resistance of 43Ω.

I then used the equation P=I2R plugging in the 1.38A and 43Ω.
This gave me a new power of 82W but the site says this is not correct. Any suggestions?
 
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  • #2
Try calculating the battery voltage in the first calculation.

This will stay constant for the second calculation.
 
  • #3
Thanks! I got it! I had it in my head that the current would be what remained constant since it was in series but wasn't quite sure about that. Thanks again!
 

FAQ: Calculate New Power when adding a Resistor

How do I calculate the new power when adding a resistor?

To calculate the new power when adding a resistor, you will need to use Ohm's Law. The formula for Ohm's Law is P = V^2/R, where P is power in watts, V is voltage in volts, and R is resistance in ohms. Simply plug in the values of the voltage and resistance before and after adding the resistor, and you will get the new power.

What is the purpose of calculating the new power when adding a resistor?

Calculating the new power when adding a resistor is important because it helps determine how much power the circuit is using. This information can be used to select the appropriate components and to ensure that the circuit is functioning properly.

Can adding a resistor increase the power in a circuit?

Yes, adding a resistor can increase the power in a circuit. This is because the addition of a resistor can change the overall resistance of the circuit, which in turn affects the power. However, it is important to note that adding a resistor does not increase the total power supplied to the circuit; it only redistributes it.

How does adding a resistor affect the current in a circuit?

Adding a resistor to a circuit can decrease the current in the circuit. This is because the resistance of the circuit increases, which reduces the flow of current. The amount of current that is diverted through the resistor depends on the value of the resistor and the overall resistance of the circuit.

Can adding a resistor affect the voltage in a circuit?

Yes, adding a resistor can affect the voltage in a circuit. This is because the addition of a resistor changes the overall resistance in the circuit, which affects the voltage drop across each component. The amount of voltage drop across the resistor will depend on its value and its position in the circuit.

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