A 3 HP 100 V DC motor is 85% efficient when...

Question 1 / 27070xps4rrEW039J4aOUSgcn

Question 1 of 27070xps4rrEW039J4aOUSgcn

A 3 HP 100 V DC motor is 85% efficient when developing its rated output. What is the current?

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Question 1 of 27070

Q

A 3 HP 100 V DC motor is 85% efficient when developing its rated output. What is the current?

🔍 Key Concepts

• Relationship between horsepower and watts (power conversion) • Definition of efficiency = output power / input power • Basic DC power formula P = V × I

💭 Think About

• First, convert the motor’s rated horsepower to watts so you know the output power in watts. • Use the efficiency to find the input power from the output power. • Once you know the input power and the voltage (100 V), solve P = V × I for current and compare with the choices.

✅ Before You Answer

• Confirm the correct HP-to-watts conversion factor before calculating. • Be sure you are using input power (not output) when applying P = V × I. • After calculating current, check that your result is close to one of the multiple-choice options and that the units are amperes (A).

Question 1 of 27070

Q

A 3 HP 100 V DC motor is 85% efficient when developing its rated output. What is the current?

A

23.93 A

B

25 A

C

20 A

D

8.5 A

Question 1 / 27070xps4rrEW039J4aOUSgcn

Question 1 of 27070xps4rrEW039J4aOUSgcn

A 3 HP 100 V DC motor is 85% efficient when developing its rated output. What is the current?

Back

Question 1 of 27070

Q

A 3 HP 100 V DC motor is 85% efficient when developing its rated output. What is the current?

🔍 Key Concepts

• Relationship between horsepower and watts (power conversion) • Definition of efficiency = output power / input power • Basic DC power formula P = V × I

💭 Think About

• First, convert the motor’s rated horsepower to watts so you know the output power in watts. • Use the efficiency to find the input power from the output power. • Once you know the input power and the voltage (100 V), solve P = V × I for current and compare with the choices.

✅ Before You Answer

• Confirm the correct HP-to-watts conversion factor before calculating. • Be sure you are using input power (not output) when applying P = V × I. • After calculating current, check that your result is close to one of the multiple-choice options and that the units are amperes (A).