Question 1

The speed may be changed from medium to low or high to low by pressing the medium-speed push button.

Accepted Answer

The speed change described would typically require pressing the low-speed button, not the medium-speed button, to achieve a change to low speed from either medium or high speeds.

Question 2

Magnetic controllers for wound rotor motors consist of one or more accelerating contactors that cut out steps of resistance in the .&#10;A)primary circuit&#10;B)stator circuit&#10;C)secondary circuit&#10;D)branch circuit

Accepted Answer

Magnetic controllers for wound rotor motors consist of one or more accelerating contactors that cut out steps of resistance in the secondary circuit, which is the rotor circuit in these types of motors.

Question 3

Magnetic controllers for wound rotor motors consist of a magnetic starter that connects the primary or stator winding to ____.&#10;A)the run contactor&#10;B)the power line&#10;C)segments of the commutator&#10;D)the starter

Accepted Answer

The primary or stator winding needs to be connected to the power line to provide the necessary voltage and current to start the wound rotor motor. A magnetic starter is used to control the flow of current to the motor. The run contactor and starter both play a role in the operation of the magnetic controller, but they do not connect the stator winding to the power line. The commutator is used in DC motors and is not relevant to wound rotor motors. The magnetic starter in a wound rotor motor connects the primary or stator winding to the power line, allowing for the control of the rotor winding through a variable resistance controller.

Question 4

A disadvantage of the method of push-button speed selection is that the motor and the driven machine can be accelerated without allowing sufficient time between steps for the rotor to gain its for each step of acceleration.

A)minimum speed
B)maximum torque
C)minimum torque
D)maximum speed

Accepted Answer

Push-button speed selection can cause the motor to accelerate too quickly without allowing the rotor to reach its maximum speed at each step, potentially leading to mechanical stress or inefficiency.

Question 5

The number of accelerating contactors depends on the desired number of speeds for the motor.

Accepted Answer

The number of accelerating contactors is dependent on the number of speeds required for the motor. As such, the statement is true. The number of accelerating contactors corresponds to the number of speeds needed for the motor. Each contactor is responsible for switching the motor's winding configuration and thus the speed of the motor. Therefore, the number of accelerating contactors will determine the number of speeds available for the motor.

Question 6

The desired time delay can be achieved by adding to the circuit to prevent too rapid an acceleration.&#10;A)compelling relays&#10;B)accelerating relays&#10;C)overload relays&#10;D)reversal relays

Accepted Answer

The answer of The desired time delay can be achieved...

Question 7

The motor starts slowly with full resistance in the primary circuit.

Accepted Answer

The answer of The motor starts slowly with full resistance...

Question 8

The resistors should have a high enough power rating to operate at any speed.

Accepted Answer

When operating at higher speeds, resistors may generate more heat due to increased current flow. Therefore, using resistors with a higher power rating ensures that they can handle the higher temperatures without burning out or becoming damaged. When resistors are used in circuitry with high speed, they may experience a high amount of power dissipation because of high-frequency signals. Therefore, it is important that resistors should have a high enough power rating to operate at any speed.

Deck 35: Push-Button Speed Selection