What is the line current of a 7 horsepower...

Question 1 of 27070YJLDDBshQakPmTceLuJf

What is the line current of a 7 horsepower motor operating on 120 volts at full load, a power factor of 0.8, and 95% efficient?

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Question 1 of 27070

Q

What is the line current of a 7 horsepower motor operating on 120 volts at full load, a power factor of 0.8, and 95% efficient?

🔍 Key Concepts

• Relationship between horsepower and watts (mechanical power to electrical power) • Single-phase power formula: P = V × I × pf × efficiency • Converting from output power to input current considering power factor and efficiency

💭 Think About

• First convert the motor's horsepower rating into watts of output power. What conversion factor do you use? • Once you have output watts, how do you adjust for 95% efficiency to find input electrical power? • Finally, how do you rearrange the single-phase power formula to solve for line current I, and which answer choice is closest to that value?

✅ Before You Answer

• Use the correct conversion: 1 hp ≈ 746 watts (mechanical output) • Remember to divide by both power factor (0.8) and efficiency (0.95) when solving for current, not multiply them. • After computing I, check if your result is in a realistic range for a 7 hp, 120 V motor (around tens of amps, not just a few amps).