Electrical Circuit Concepts

1. Determine the distance from the start of the circuit to the load center.

• Calculate the voltage drop across the circuit.

• Estimate the distance based on the load type.

• Measure the circuit length directly.

• Use a formula to determine the circuit capacity.

2. A three-phase, 480-V, 30-A branch circuit powers ten 500-W motors. What is the actual connected and potential future load?

• Actual connected load: 10 A; Potential future load: 25 A

• Actual connected load: 6.01 A; Potential future load: 30 A

• Actual connected load: 12.5 A; Potential future load: 45 A

• Actual connected load: 8 A; Potential future load: 20 A

3. Find the distance to the load center L of a single-phase circuit with 6 lamps, where the total length from supply to the end is 120 feet, each lamp is 15 feet apart, and each lamp has a load of 1.5 A.

• 45 feet

• 15 feet

• 30 feet

• 60 feet

4. How is the power factor (PF) calculated?

• PF = cos(φ) = P / S

• PF = tan(φ) = Q / P

• PF = S / Q

• PF = P / V

5. What does the demand factor represent?

• The difference between maximum demand and minimum demand.

• The ratio of maximum demand to total connected load.

• The total connected load divided by the average demand.

• The average demand over a specified period of time.

6. Calculate the distance from the power source to the load area.

• The distance can be calculated using voltage.

• The distance is determined by the specific measurements taken.

• The distance is irrelevant to the load area.

• The distance is always 10 meters.

7. In a three-phase, 480-V, 30-A circuit supplying ten 500-W motors, what are the current loads?

• 5.77 A per motor

• 10 A per motor

• 3.5 A per motor

• 7.5 A per motor

8. For a single-phase circuit with 6 lamps, if the total length is 120 feet and each lamp is spaced 15 feet apart, what is the distance to the load center?

• 45 feet

• 75 feet

• 60 feet

• 90 feet

9. What is the formula for determining the power factor?

• PF = P / S or PF = cos(φ)

• PF = S / P

• PF = P * S

• PF = P + S

10. The demand factor is the relationship between which two values?

• Actual supply and maximum possible supply

• Minimum demand and average demand

• Actual demand and maximum possible demand

• Projected demand and actual sales