What formula is used to calculate power loss in a conductor?

• A. P = E/R
• B. P = I * E
• C. P = I^2 * R
• D. P = R * V

Answer: (C)

The power loss in a conductor is calculated using the formula P = I² * R. This relationship stems from Ohm's Law, which states that voltage (V) across a conductor is equal to the current (I) flowing through it multiplied by the resistance (R) of that conductor.

When considering power, it is expressed in watts, which is calculated as the product of voltage and current (P = V * I). To express everything in terms of current, we can substitute voltage from Ohm's Law. Rearranging Ohm's Law gives us V = I * R. When substituting this into the power formula (P = V * I), we get P = (I * R) * I, which simplifies to P = I² * R.

This equation shows how power loss due to heat in a conductor increases with the square of the current while being directly proportional to the resistance. This is particularly important in electrical systems as it allows engineers and electricians to calculate the efficiency and potential overheating issues of conductors in real-world applications.