Back to Electric Power — Problem 4 · Task Set 11

Exercises: Electric Power

Work through each section in order. Show your work where indicated.

Grade 11·22 problems·~30 min·OpenStax Physics (High School)·section·sec-19-4

Work through problems with immediate feedback

Fluency Practice

Decision tree showing which power formula to use: P=IV when given I and V, P=I-squared-R when given I and R, P=V-squared-over-R when given V and R, with the V and R row highlighted

A resistor has $V = 24\ \text{V}$ across it and $R = 8\ \Omega$ . Which formula should you use to calculate power directly from these two values, and what is the result?

$P = IV$ ; find $I$ first: result is $72\ \text{W}$

$P = I^2R$ ; result is $72\ \text{W}$

$P = V^2/R$ ; result is $72\ \text{W}$

$P = V^2/R$ ; result is $576\ \text{W}$