Power Rating

If there are two resistors with the same 200 ohm resistance, but one has a 1/2 Watt power supply and the other has a 3/4 Watt, is even possible to to determine which resistor has the 1/2 Watt power rating without damaging it? How?

My understanding is that all of the equation lead me to the same Watt amount because V=I R and P = VI when using the same resistance value dont have different Watts. Is this possible?

by canbaz18
September 02, 2019

you are right. resistor's wattage is only used to show how much wattage it can work without damage. How much wattage it gets dependent on what current through it or what voltage on it.

by wangwg88
September 03, 2019

If you are trying to find which is which: Connect the two resistors in parallel across a 10 volt source and put your finger on each--the 1/2 watt will be hotter than the 3/4 watt. Remember- P=(e^2)/r so each resistor will receive 10*10/200=0.5 watts. The 1/2 watt resistor will be at its limit so will be very hot. The 3/4 watt resistor will at 2/3 its limit so will not be as hot.

by Foxx
September 04, 2019
Add comment...

Please sign in or create an account to comment.


No Answers

No answers yet. Contribute your answer below!


Your Answer

You must log in or create an account (free!) to answer a question.

Log in Create an account


Go Ad-Free. Activate your CircuitLab membership. No more ads. Save unlimited circuits. Run unlimited simulations.

Search Questions & Answers


Ask a Question

Anyone can ask a question.

Did you already search (see above) to see if a similar question has already been answered? If you can't find the answer, you may ask a question.


About This Site

CircuitLab's Q&A site is a FREE questions and answers forum for electronics and electrical engineering students, hobbyists, and professionals.

We encourage you to use our built-in schematic & simulation software to add more detail to your questions and answers.

Acceptable Questions:

  • Concept or theory questions
  • Practical engineering questions
  • “Homework” questions
  • Software/hardware intersection
  • Best practices
  • Design choices & component selection
  • Troubleshooting

Unacceptable Questions:

  • Non-English language content
  • Non-question discussion
  • Non-electronics questions
  • Vendor-specific topics
  • Pure software questions
  • CircuitLab software support

Please respect that there are both seasoned experts and total newbies here: please be nice, be constructive, and be specific!

About CircuitLab

CircuitLab is an in-browser schematic capture and circuit simulation software tool to help you rapidly design and analyze analog and digital electronics systems.