NCCER Electrical Module 2 Level 2 exam 2023 with 100% correct answers
How DC motors operate? - correct answer -Magnetic lines of force are continuous and always form closed loops; Magnetic lines of force do not cross.
Armature: (Definition) - correct answer -The rotating windings of a DC motor.
The ____ is a movable electromagnet located between the poles of another fixed permanent (field) magnet as shown. - correct answer -Armature
A twisting force called ______ must be developed. _____ is produced by mounting a loop in a fixed magnetic field and as long as the fields of the magnet and armature interact. - correct answer -Torque
Commentator: (Definition) - correct answer -A device used on electric motors or generators to maintain a unidirectional current.
In the neutral plane, no ____ is produced and the rotation of the armature should stop - correct answer -Torque
A _____ is produced by the fields poles, and a loop of wire in the armature turns and cuts this magnetic field. - correct answer -Magnetic field
CEMF - correct answer -Counter electromotive force (CEMF)
Horsepower: (Definition) - correct answer -The rated output capacity of the motor. It is based on breakdown torque, which is the maximum torque a motor will develop without an abrupt drop in speed.
Horsepower: (Equation) - correct answer -Hp= Watts/746 Types of DC motors - correct answer -Shunt
Series
Compound
Types of AC motors - correct answer -Synchronous and Induction (Single and Polyphase)
Periodic duty: (Definition) - correct answer -Intermittent operation at a substantially constant load for a short and definitely specified time.
Revolutions per minute (rpm): (Definition) - correct answer -The approximate full-load speed at the rated power line frequency. The speed of a motor is determined by the number of poles in the winding.
Rotation: (Definition) - correct answer -For single-phase motors, the standard rotation, unless otherwise noted, is counterclockwise facing the lead or opposite shaft end. All motors can be reconnected at the terminal board for opposite rotation unless other wise indicated.
Synchronous speed: (Definition) - correct answer -The speed of the revolving field of the stator, which is dependent on the supply frequency and number of poles in a stator winding.
Field poles: (Definition) - correct answer -The stationary portion of a DC motor that produces the magnetic field.
The name of the motor part that rotates during operation is the ____. - correct answer -Armature
The principle reason for developing the brushless DC motor was to ___. - correct answer -eliminate commutator problems
The electrical energy required to produce 1hp of mechanical energy is _____. - correct answer -746W
When there is a wide variation in both torque and speed requirements, such as a blower or hoist, use a _____. - correct answer -series DC motor
How DC motors operate? - correct answer -Magnetic lines of force are continuous and always form closed loops; Magnetic lines of force do not cross.
Armature: (Definition) - correct answer -The rotating windings of a DC motor.
The ____ is a movable electromagnet located between the poles of another fixed permanent (field) magnet as shown. - correct answer -Armature
A twisting force called ______ must be developed. _____ is produced by mounting a loop in a fixed magnetic field and as long as the fields of the magnet and armature interact. - correct answer -Torque
Commentator: (Definition) - correct answer -A device used on electric motors or generators to maintain a unidirectional current.
In the neutral plane, no ____ is produced and the rotation of the armature should stop - correct answer -Torque
A _____ is produced by the fields poles, and a loop of wire in the armature turns and cuts this magnetic field. - correct answer -Magnetic field
CEMF - correct answer -Counter electromotive force (CEMF)
Horsepower: (Definition) - correct answer -The rated output capacity of the motor. It is based on breakdown torque, which is the maximum torque a motor will develop without an abrupt drop in speed.
Horsepower: (Equation) - correct answer -Hp= Watts/746 Types of DC motors - correct answer -Shunt
Series
Compound
Types of AC motors - correct answer -Synchronous and Induction (Single and Polyphase)
Periodic duty: (Definition) - correct answer -Intermittent operation at a substantially constant load for a short and definitely specified time.
Revolutions per minute (rpm): (Definition) - correct answer -The approximate full-load speed at the rated power line frequency. The speed of a motor is determined by the number of poles in the winding.
Rotation: (Definition) - correct answer -For single-phase motors, the standard rotation, unless otherwise noted, is counterclockwise facing the lead or opposite shaft end. All motors can be reconnected at the terminal board for opposite rotation unless other wise indicated.
Synchronous speed: (Definition) - correct answer -The speed of the revolving field of the stator, which is dependent on the supply frequency and number of poles in a stator winding.
Field poles: (Definition) - correct answer -The stationary portion of a DC motor that produces the magnetic field.
The name of the motor part that rotates during operation is the ____. - correct answer -Armature
The principle reason for developing the brushless DC motor was to ___. - correct answer -eliminate commutator problems
The electrical energy required to produce 1hp of mechanical energy is _____. - correct answer -746W
When there is a wide variation in both torque and speed requirements, such as a blower or hoist, use a _____. - correct answer -series DC motor
