4A Final

What's the resistance of two wires where each has a voltage drop of 3.60V (7.20V total) and the current flowing in the circuit is 36A?

0.20 ohms

If the output of a 10 hp dc motor is 7,460W (746W × 10 hp) and the input is 9,600W (40A × 240V), what’s the efficiency of the motor?

0.78

What’s the power factor for a ballast rated 0.50A at 277V supplying a 2 × 4 fixture containing four 32W bulbs?

0.92

What's the resistance total of a 10-ohm, a 6-ohm, and a 3-ohm resistor connected in parallel?

1.67 ohms

What is the kVA load for transformer sizing for eighty-nine, 150W electric discharge luminaires having a power factor of 95 percent?

14 kVA

What's the current flow in amperes through a 1,800W load rated 120V when connected to a 120V power source?

15A

The total resistance of three 6-ohm resistors in parallel is _____ ohms.

2

What's the true power of a 24A load rated 120V with a power factor of 95 percent?

2,736W

What's the secondary wire power loss of a 112.50 kVA transformer if the secondary current rating is 135A and the winding has a resistance of 0.16 ohms?

2,916W

What's the turns ratio of a transformer if the primary phase voltage is 480V and the secondary is 208V?

2.31:1

The total resistance of five 14-ohm resistors in parallel is _____ ohms.

2.8

What's the power loss for a 2-wire, 8 AWG circuit carrying 34A at 240V having a voltage drop of three percent?

245W

What size hp motor produces output power of 18kW?

25hp

The resistance of a coffee pot is 10 ohms and the resistance of a toaster oven is approximately 6 ohms. What's the total resistance of the two appliances if they're connected in parallel?

3.75 ohms

What's the voltage drop of 125 ft of 12 AWG wire (0.24 ohms) on a balanced 3-wire, 120/240V multiwire circuit supplying a 16A load?

3.80V

What's the height of a light pole if the distance from the pole is 48 ft, the angle is 30°, and the eye level is 6 ft above the ground level?

34ft

What length of cable is needed if a 30-ft tall pole needs a guy wire installed 22 ft away from the pole?

38ft

What's the area of a raceway that has an inside diameter of 2½ in.?

4.91 sq in.

What's the turns ratio of a transformer if the primary winding voltage (EP) is 240V and the secondary winding voltage (ES) is 60V?

4:1

What's the height of a building if the distance from where you're standing is 100 ft from the building, the angle is 26°, and the eye level is 6 ft above the ground level?

55ft

If the input power to a load is 7,460W and the equipment is rated at 92.50 percent efficiency, what's the output power rating in watts?

6,900W

What's the motor nameplate full-load amperes (FLA) for a 15 hp, 230V, single-phase motor having an efficiency rating of 93 percent and a power factor of 87 percent?

60A

What's the motor nameplate full-load amperes (FLA) for a 50 hp, 480V, three-phase motor having an efficiency rating of 80 percent and a power factor of 90 percent?

62A

What's the power loss of a 2-wire circuit carrying 12A having a length of 100 ft with two 12 AWG wires each having a resistance of 0.22 ohms?

64W

What's the voltage drop of 180 ft of 12 AWG wire (0.347 ohms) supplying a 17A load?

6V

What's the voltage drop of 180 ft of 12 AWG wire (0.347 ohms) supplying a 17A load?

6v

What's the primary voltage of a transformer if the turns ratio is 30:1 and the secondary voltage is 240V?

7,200V

A 12-ohm coffee pot is connected in parallel to a 16.09-ohm skillet and wired with a wire having a resistance of 0.07 ohms. What's the total resistance of the loads and the wires of this series-parallel circuit?

7.04 ohms

What's the primary wire power loss of a 50 kVA transformer if the primary current rating is 60A and the winding has a resistance of 0.22 ohms?

792W

What's the apparent power in VA of a fluorescent ballast with a power factor of 90 percent when it's connected to two 40W bulbs?

90 VA

What's the primary and secondary line current at full load for a 480/240V, 75 kVA, three-phase transformer?

90/180A