How to convert ohms to watts?

How can you convert a resistor of 270.4 watts to ohms without having been given voltage or current?

• Answer:

  There is no way to make the conversion. The wattage given as that of the resistor is only the amount of power it is dissipating. It's the heat the resistor is radiating. The resistor is said to be using or radiating 270.4 watts. (That's a lot of wattage! How hot would a 270 watt incandescent lamp get? Very hot.) A watt is sometimes called a volt-amp. That's because watts equals volts times amps. And it's easy to see how that works with an example including the approximately 270 watts set down in the question. As regards that approximately 270 watts specified, if the resistor was a 1 ohm resistor and had 270 amps of current flowing through it, the 270 watts would be the wattage the resistor would be radiating. If the resistor was a 270 ohm resistor and had 1 amp of current flowing through it, it would (also) be radiating 270 watts. See how that works? An unlimited number of variations on the theme exist. To find the resistance of the resistor, one of two things must be known in addition to the wattage the resistor is running at. Either the voltage across the resistor or the current flow through the resistor must be specified to "finish" the problem.