Electrical Power Loss Equations Confusion

In summary, the equation for power loss is often represented as I^2*R rather than V*R. This is because power is not equal to V*R, but rather V^2/R or V*I. The use of I/R to represent V is incorrect. However, depending on the specific problem, different equations can be used to find power.
  • #1
Kevin Shen
7
2
Why is the equation Power Loss = I^2*R rather than Power Loss = V*I?
What I mean is why use I/R to represent V?
Also if Power Loss is equivalent to V*R, doesn't step up transformers which creating higher voltage also cause Power Loss to increase which contradicts to textbooks stating that power loss decreases if voltage rises given that power supply is same?
 
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  • #2
You could use V*I or V^2/R to represent power (not V*R). But you need to understand how to use it. Look at a resistor. If the resistor has 50 ohms, and there is 10 volts across it, how do you find the power dissipated in the resistor? You can find the current in the resistor, then multiply current x voltage (across the resistor). If you look at Ohm's Law [V = I*R, not I/R], then you can substitute one of these values for it's equivalent combination of the other 2.
 
  • #3
Kevin Shen said:
Why is the equation Power Loss = I^2*R rather than Power Loss = V*R?What I mean is why use I/R to represent V?
Power isn't V*R it is either V2/R or V*I. And V isn't I/R, it is I*R.

But in either case, as said above you can use different equations for different problems depending on what you need.
 
  • #4
russ_watters said:
Power isn't V*R it is either V2/R or V*I. And V isn't I/R, it is I*R.

But in either case, as said above you can use different equations for different problems depending on what you need.
Yeah I realized I made the error and I get it now :)
 
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1. What are electrical power loss equations and why are they important?

Electrical power loss equations are mathematical equations used to calculate the amount of energy lost in a circuit due to resistance. They are important because they help engineers and scientists understand the efficiency of electrical systems and make improvements to reduce energy waste.

2. How do I calculate power loss in a circuit?

The most common equation used to calculate power loss is P=I^2R, where P is power loss in watts, I is current in amps, and R is resistance in ohms. Another equation often used is P=I^2Rt, where t is time in seconds. These equations can be modified depending on the specific circuit and type of energy loss.

3. What factors affect power loss in a circuit?

There are several factors that can affect power loss in a circuit, including the type of material used for wiring, the length and thickness of the wires, and the temperature of the circuit. Higher resistance materials, longer and thinner wires, and higher temperatures can all increase power loss.

4. How can I reduce power loss in a circuit?

To reduce power loss in a circuit, you can use materials with lower resistance, shorter and thicker wires, and keep the circuit at a lower temperature. Additionally, using more efficient components and reducing the number of connections in the circuit can also help reduce power loss.

5. Are there any limitations to electrical power loss equations?

While electrical power loss equations are useful tools for understanding energy efficiency, they do have limitations. These equations assume ideal conditions and do not account for external factors such as electromagnetic interference or power supply fluctuations. Additionally, they may not accurately represent more complex circuits with varying resistances.

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