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How to calculate the power absorbed by an element with just watts?

a) Power = Voltage × Current
b) Power = Current × Resistance
c) Power = Voltage × Resistance
d) Power = Energy/Time

1 Answer

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Final answer:

The formula for calculating the power absorbed by an element in watts is Power = Energy/Time. When dealing with a resistor, power can be calculated using the formulas P = IV, P = I²R, or P = V²/R, based on the available information about voltage, current, and resistance.

Step-by-step explanation:

To calculate the power absorbed by an element when you know the watts, the correct formula is d) Power = Energy/Time. However, if you specifically have a resistor and you are given the voltage across it or the current through it, you can use different formulas derived from Joule's law.

For power dissipated in a resistor, you can use the formula P = IV (where P is power in watts, I is current in amperes, and V is voltage in volts), as well as the variants P = I²R (where R is resistance in ohms) if you know the current and resistance, or P = V²/R if you have the voltage and resistance. These formulas are all dimensionally equivalent and can be used based on the known quantities.

Therefore, another correct answer for the formula for power dissipated in a resistor, based on the provided options, could be c) The formula for the power dissipated in a resistor is P = I²R. This is evident from the given information that for a resistor with a current of 0.600 A and a resistance of 1.00 ohm, the power dissipation would be P = (0.600 A) ² (1.00 ohm) = 0.360 W.

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