FE Exam Flashcards with correct answers

What are three different types of grounding that may be necessary in an electrical system design? correct answers1. power system grounding (for normal system operation) 2. equipment grounding (for personnel safety) 3. lightning or surge protection grounding (for equipment protection) For what purpose are ferrite beads used? correct answersFrom an electromagnetic compatibility (EMC) standpoint, these beads are used to attenuate unwanted (magnetic field) high-frequency signals while allowing functional low-frequency signals (e.g., power) to pass.? What term describes the unintended electromagnetic coupling that occurs between wires in close proximity? correct answersCrosstalk What is the formula for the voltage induced in the conductor of a motor or generator? correct answersE=Blv What is the name of the following rotating AC machinery ratio? safe load & nameplate load correct answersThe service factor is given by this ratio. What types of power losses are determined by testing a rotating machine at rated speed with no load, while measuring the input power at the stated conditions? correct answersThis is how mechanical losses are determined. What type of motor turns at a constant steady-state speed, regardless of the load? correct answersA synchronous motor operates under these conditions. Which is more likely to be varied in order to control an induction motor's speed: number of poles, line voltage, supply frequency, or rotor resistance? correct answersInserting a rotor resistance is the most common way to vary this motor's speed, followed by changing the supply frequency, the line voltage, or the number of poles.