How Much Power Does Each Resistor Dissipate?

In summary, the problem is asking for the power dissipated by two resistors in a circuit. The equations used are P=IV and I=V/R. By finding the current, Ohm's law can be used to find the voltage drop across the resistors. The total power dissipated by the resistors is 204 watts.
  • #1
cwesto
18
0

Homework Statement



How much power is dissipated by the 12[tex]\Omega[/tex] resistor in the figure?
32.jpg

PR1=______W
How much power is dissipated by the 18 resistor in the figure?
PR2=______W

Homework Equations



P=IV
I=[tex]\frac{V}{R}[/tex]

The Attempt at a Solution



P=[tex]\frac{V}{R}[/tex]*V
P=V2/R

P=12*12/12=12V

After solving for my equation I plugged in my numbers but it's not correct. All I need are a few hints to lead me in the right direction. Thanks!
 
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  • #2
Please show the details of your calculations so we can see what you're doing. You need to find the voltage drop across the resistor you're interested in. Note this will NOT be 12V.
 
  • #3
Try finding either the current through the resistors or the voltage across the resistors.
 
  • #4
What is the current in the circuit?

The power is

P=RI^2

Where R is the resistanse of the component and I is the current through the component
 
  • #5
the current is 2 amps. what is the equation to find the voltage drop?
 
  • #6
It's Ohm's law. But all you need is the current. Try arrangin the power equation so that you only need to use the current and resistor. Is that the current for the whole circuit? If so it's incorrect.
 
  • #7
wait sorry they don't give the current my bad. i was looking at another problem. sorry
all the information up there is what they give me to solve the problem, nothing more.
 
  • #8
cwesto said:
all the information up there is what they give me to solve the problem, nothing more.

You can find the current using the information in the problem. Okay, you know Ohm's law and you probably can create an Req for the two resistor in the circuit. That's should be enough to find the current.
 
  • #9
So I found the power in each resistor using P=I^2R, plugging in the current going through that resistor and the resistance and I get the sum of the power being 204 watts. This is not what I got in part c. Is it supposed to be?
 
  • #10
sweetdion said:
So I found the power in each resistor using P=I^2R, plugging in the current going through that resistor and the resistance and I get the sum of the power being 204 watts. This is not what I got in part c. Is it supposed to be?

Hello sweetdion,

I think you might have posted to the wrong thread. :biggrin:
 
  • #11
collinsmark said:
Hello sweetdion,

I think you might have posted to the wrong thread. :biggrin:

Haha, yes, thank you. :blushing:
 

Related to How Much Power Does Each Resistor Dissipate?

1. What is the definition of "Power Dissipated by Resistor"?

The power dissipated by a resistor is the amount of energy that is converted into heat when an electric current passes through it.

2. How is the power dissipated by a resistor calculated?

The power dissipated by a resistor can be calculated using the formula P = I^2 * R, where P is power in watts, I is current in amperes, and R is resistance in ohms.

3. What factors affect the power dissipated by a resistor?

The power dissipated by a resistor depends on the current flowing through it and the resistance of the resistor. It also depends on the temperature of the resistor and the surrounding environment.

4. What is the relationship between power and resistance in a resistor?

The power dissipated by a resistor is directly proportional to its resistance. This means that as the resistance increases, the power dissipated also increases, and vice versa.

5. How does the power dissipated by a resistor affect the circuit?

The power dissipated by a resistor can affect the overall performance and efficiency of a circuit. As more power is dissipated, the resistor may heat up and potentially lead to malfunctions or failures in the circuit. It is important to choose a resistor with the appropriate power rating for a given circuit to prevent these issues.

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