Question 1

Series impedance control is accomplished by connecting a tapped inductor in parallel with the motor.

Accepted Answer

Series impedance control is accomplished by connecting a tapped inductor or resistor in series with the motor, not in parallel. This method is used to limit the current or adjust the voltage applied to the motor.

Question 2

Triac light dimmers are intended to be used with resistive loads such as incandescent lamps.

Accepted Answer

Triac light dimmers are designed to work with resistive loads such as incandescent lamps. They may not work effectively with other types of loads such as LED or fluorescent lamps.

Question 3

Two common methods used to control the voltage applied to the motor are autotransformer control and ____.&#10;A) triac control&#10;B) parallel impedance&#10;C) steps speed control&#10;D) diac control

Accepted Answer

Autotransformer and triac control are the two common methods used to control the voltage applied to the motor. Parallel impedance and step speed control are not methods used for this purpose. Diac control is also not commonly used for motor voltage control.

Question 4

Variable-speed control for small motors is accomplished by controlling the amount of ____ applied to the motor or by inserting impedance in series with the stator winding.&#10;A) current&#10;B) pressure&#10;C) voltage&#10;D) amperage

Accepted Answer

Variable-speed control for small motors is accomplished by controlling the amount of voltage applied to the motor. This is typically done through the use of a phase-controlled rectifier or by adjusting the supply voltage using a microcontroller or other electronic circuitry. Inserting impedance in series with the stator winding is also a method of controlling motor speed, but it is less commonly used for small motors.

Question 5

A light dimmer can be adapted for use as a motor speed controller.

Accepted Answer

The answer of A light dimmer can be adapted for...

Question 6

Permanent-split capacitor motors and shaded-pole motors are generally used for variable-speed control because they operate without having to disconnect a set of start windings with a ____ or starting relay.

A) membrane switch
B) centrifugal switch
C) pressure switch
D) rotary switch

Accepted Answer

Centrifugal switches are used to disconnect the start windings in a motor once it reaches a certain speed. Permanent-split capacitor motors and shaded-pole motors do not require this type of switch because they are designed to operate without it. Therefore, B is the correct answer because it describes the type of switch that is not needed for these types of motors.

Question 7

One type of variable-voltage control uses a triac to control the amount of voltage applied to the motor.

Accepted Answer

A triac is a semiconductor device that is commonly used as a switch to control the amount of voltage applied to a motor or other electronic device. By controlling the timing and duration of the electrical pulses sent to the triac, the voltage can be effectively modulated, allowing for variable speed control of the motor.

Question 8

Variable-speed motors are commonly used to operate light loads such as ceiling fans and blower motors.

Accepted Answer

Variable-speed motors are indeed commonly used for lighter loads such as ceiling fans and blower motors, as they allow for more precise control over the speed and can help save energy.

Question 9

A common method of controlling the speed of ____ is to connect impedance in series with the stator winding.&#10;A) servo motors&#10;B) brushed DC motors&#10;C) brushless DC motors&#10;D) small AC motors

Accepted Answer

Small AC motors are commonly controlled by connecting impedance in series with the stator winding. This method is known as series impedance control and it reduces the amount of current flowing through the stator winding, resulting in a lower magnetic flux and a decrease in the motor speed.

Question 10

The two main types of single-phase AC motors used for variable-speed control are the permanent-split capacitor motor and the ____.&#10;A) brushless AC servo motor&#10;B) stepper motor&#10;C) linear motor&#10;D) shaded-pole motor

Accepted Answer

The two main types of single-phase AC motors used for variable-speed control are the permanent-split capacitor motor and the shaded-pole motor. These motors are widely used in various applications due to their simplicity and effectiveness in controlling speed.

Deck 27: Variable-Speed Motor Control