🔍 Key Concepts
• Horsepower (HP) to watts (W) conversion and why we convert mechanical power to electrical power units
• The relationship between input power, output power, power factor, and efficiency for an AC motor
• Using P = V × I × pf for single‑phase power and how efficiency changes the equation
💭 Think About
• First, convert the 7 HP mechanical output to watts. What number do you multiply HP by to get watts?
• Once you have output power in watts, how do you adjust it for 95% efficiency to find the electrical input power?
• With input power known, how can you rearrange P = V × I × pf to solve for the line current I at 120 V and pf = 0.8?
✅ Before You Answer
• Be sure you are using input power, not output power, in the P = V × I × pf formula
• Check that you applied efficiency as a ratio (e.g., 0.95), not as 95 added or subtracted
• After calculating current, compare the value with each option and confirm that your units are watts, volts, and amperes are all consistent