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Flashcards in Unit 19 Deck (18)
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1

Inductors and capacitors are energy _____ devices

Storage

2

The cost of electricity consumed is based on the unit of watts, and is billed on the number of _____ times the cost per _____

kilowatt-hours ; kWh

3

Utility companies charge based on what?

Power consumed

4

True power is expressed in what?

Watts

5

How do you calculate true power in an ac circuit?

Volts x Amps x Power Factor Multiplier

6

If you measure voltage and current in an inductive or capacitive circuit, and then multiply them together, you will obtain the circuit's _______ power

Apparent

7

Apparent power is expressed in what?

Volt-amperes

8

Because the voltage and current reach their zero and peak values at the same time, there is no leading or lagging of the current to the voltage, therefore, the power factor of the load is 100 percent, this condition is called what?

Unity power factor

9

What is the formula used for efficiency calculations?

Efficiency = Output Watts / Input Watts

10

The relationship between true power, apparent power, and power factor can be stated as _______

PF = TP / AP

11

VA is used for sizing ______ and _______

Circuits ; equipment

12

When energy is not used for its intended purpose the condition is called ____

Power loss

13

Efficiency describes how much ____ energy is used for its intended useful purpos

Input

14

True power is the energy _____

Consumed

15

There will be power losses in these three areas

Conductors, the power supply, and the load itself

16

How do you calculate true power in a dc circuit?

Volt x Amps

17

Power factor is the ratio of circuit _______ to circuit _____ and it is expressed as a percentage

Resistance ; impedance

18

The degree of power loss in watts is indicated by the term _____

Efficiency