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

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