Electrical Power Quiz

What is the ratio between the useful (true) power (kW) and the total (apparent) power (kVA) known as?

• Electrical efficiency

• Reactive power

• Power factor

• Harmonic distortion

What is the ideal power factor value for efficient electrical power conversion?

• 0.5

• 0.95

• 1.0

• 0.75

What can a poor power factor due to inductive loads be improved by?

• Decreasing the voltage

• Adding power factor correction equipment

• Increasing the harmonic content

• Reducing the load

What is the result of a load with a power factor of 0.8 compared to a load with a power factor of 1.0?

• It results in the same power consumption.

• It results in much higher losses in the system.

• It results in a lower electricity bill.

• It results in no change in the efficiency.

What percentage of the total load on the motor is typically the magnetizing current?

• 20-60%

• 10-30%

• 40-80%

• 70-90%

If a motor with a current draw of 10 Amps and a power factor of 0.75 is considered, what is the useful power from the motor?

• 1.725kW

• 2.3kW

• 7.5kW

• 10kW

What is the power factor (pf) formula as the cosine of the angle between useful power and total power?

• pf = Useful power (kW) / total power (kVA)

• pf = total power (kVA) / Useful power (kW)

• pf = cos θ

• pf = sin θ

What is one of the environmental benefits of applying the correct power factor correction?

• Increase in power consumption

• Increase in greenhouse gas emissions

• Reduction of power consumption

• Increase in fossil fuel depletion

What is typically the power factor that most Network Operating companies now penalize for power factors below?

• 0.7

• 0.8

• 0.9

• 1.0

What is the purpose of power factor correction equipment?

• To increase the electricity bill

• To reduce the amount of useful power

• To neutralize as much of the magnetizing current as possible

• To increase the electrical burden on cables and electrical components