Subelement B: Electrical Math— Topic 13: Power Relationships
Question 3-13B3
Element 3 (GROL)746 watts, corresponding to the lifting of 550 pounds at the rate of one-foot-per-second, is the equivalent of how much horsepower?
Explanation
One mechanical horsepower is defined as the power required to lift 550 pounds a distance of one foot in one second. The question explicitly states that 746 watts corresponds to this exact rate of work (lifting 550 pounds at one-foot-per-second). Therefore, by definition, 746 watts is the equivalent of exactly one horsepower. This conversion factor (1 HP = 746 watts) is fundamental in physics and engineering, including amateur radio when discussing transmitter power output. Options A, B, and C represent fractions of this defined relationship.
Related Questions
3-13B1 What does the power factor equal in an R-L circuit having a 60 degree phase angle between the voltage and the current?3-13B2 If a resistance to which a constant voltage is applied is halved, what power dissipation will result?3-13B4 In a circuit where the AC voltage and current are out of phase, how can the true power be determined?3-13B5 What does the power factor equal in an R-L circuit having a 45 degree phase angle between the voltage and the current?3-13B6 What does the power factor equal in an R-L circuit having a 30 degree phase angle between the voltage and the current?