Question 412Electricity/Electronics - Assistant Engineer70% to pass
If a DC motor has its armature and field connected across a resistor when the motor is disconnected from its power supply, what statement is true?
AI Explanation
The correct answer is D) The motor will slow down by the process of dynamic braking.
When a DC motor's armature and field are connected across a resistor while the motor is disconnected from its power supply, this sets up a dynamic braking circuit. In this configuration, the motor's momentum causes it to generate a back EMF voltage, which creates a current flowing through the resistor. This current opposes the motor's rotation, resulting in the motor slowing down through the process of dynamic braking.
The other answer choices are incorrect because they do not accurately describe the function of this circuit configuration. Across the line starting, automatic strip heaters, and reversing controller circuits involve different electrical connections and purposes for DC motors.
Related Questions
#410 Refer to figures "1" and "2" of the basic synchronous transmission system shown in the illustration. Figure "1" shows a properly connected system where the receiver TR remains in correspondence with the transmitter TX. In figure "2", although properly zeroed, the receiver goes out of correspondence with the transmitter due to improper connections resulting in reverse torque direction. Which connection error results in this behavior? Illustration EL-0149 #411 As shown in the illustration, which brush holder is of the reaction type? Illustration EL-0029 #413 In terms of voltage potential and current sources, how are shunt wound, series wound, and compound wound DC motors designed to operate? #414 Which of the following statements describes what will happen when both the polarity of the field poles, and the direction of current to the brushes of a DC motor are reversed? #415 As shown in figure "B" of the illustration, what does the M-G set's three-phase drive motor mechanically drive? Illustration EL-0101