How much current does a 30-volt, 1/2 horsepower motor that is 85 percent efficient draw from the bus?

How much current does a 30-volt, 1/2 horsepower motor that is 85 percent efficient draw from the bus?

• A. 10.5 amperes
• B. 12.3 amperes
• C. 14.6 amperes
• D. 16 amperes

Answer: (C)

To determine how much current a 30-volt, 1/2 horsepower motor that operates at 85% efficiency draws from the bus, you can use the following steps: 1. **Convert horsepower to watts**: One horsepower is equivalent to approximately 746 watts. Therefore, a 1/2 horsepower motor would be: \[ \text{Power (in watts)} = \frac{1}{2} \times 746 = 373 \text{ watts} \] 2. **Adjust for efficiency**: Since the motor is 85% efficient, you need to find the input power required. The input power can be calculated using the formula: \[ \text{Input Power} = \frac{\text{Output Power}}{\text{Efficiency}} = \frac{373 \text{ watts}}{0.85} \approx 438.24 \text{ watts} \] 3. **Calculate current**: Using Ohm's Law, which states that Power (P) is equal to Voltage (V) times Current (I), you can rearrange it to find the current: \[ I = \frac{P}{V} \]

To determine how much current a 30-volt, 1/2 horsepower motor that operates at 85% efficiency draws from the bus, you can use the following steps:

1. Convert horsepower to watts: One horsepower is equivalent to approximately 746 watts. Therefore, a 1/2 horsepower motor would be:

[

\text{Power (in watts)} = \frac{1}{2} \times 746 = 373 \text{ watts}

]

2. Adjust for efficiency: Since the motor is 85% efficient, you need to find the input power required. The input power can be calculated using the formula:

[

\text{Input Power} = \frac{\text{Output Power}}{\text{Efficiency}} = \frac{373 \text{ watts}}{0.85} \approx 438.24 \text{ watts}

]

3. Calculate current: Using Ohm's Law, which states that Power (P) is equal to Voltage (V) times Current (I), you can rearrange it to find the current:

[

I = \frac{P}{V}

]