Deck 1: Transformers and Power Supplies

Question 1

Most control circuits in industry today utilize AC to provide electrical energy for devices that control equipment.

Answer 1

False

Question 2

The transformer must be sized to handle the full load current for all of the devices that may be in operation at any given time.

Answer 2

True

Question 3

Voltage ____________________ in transformers is the difference between the no-load voltage and the full-load voltage.

Answer 3

regulation

Question 4

The main power that is supplied to industries in the United States is three phase (3F), ____ volts alternating current (VAC), at a frequency of 60 Hertz (Hz).

A) 480
B) 240
C) 120
D) 24

Question 5

What is the standard frequency that is utilized in Europe, Asia, and many countries throughout the world?

A) 45 Hz
B) 50 Hz
C) 55 Hz
D) 60 Hz

Question 6

On a circuit diagram, the rule for assigning wire numbers states that the wire number
will change every time the wire goes through a device.

Question 7

Temperature ____ in a transformer is the amount by which the temperature of the windings and insulation exceeds the existing ambient or surrounding temperature.

A) overload
B) overvoltage
C) rise
D) upswing

Question 8

Utility supply problems can be overcome by connecting a(n) ____ between the utility supply and sensitive load equipment.

A) uninterruptible power system (UPS)
B) battery module
C) pulse width modulation (PWM)
D) ampacity conductor

Question 9

The transformer that converts the 480 VAC to 120 VAC for use in the control circuit is called the ____________________.

Question 10

The primary purpose of a(n) ____________________ is to convert the incoming AC voltage to a DC voltage for use by the control circuit.