Neiep 600 Final Exam Review 2023

Zener current will decrease - ANSWER-Refer to figure 1. If the load resistance R2 is reduced by half what happens what happens to zener diode? 4v - ANSWER-Refer to figure 1. The zener diode is designed to breakdown at 6VDC what is the voltage drop across R1 with a constant DC supply of 10VDC 30 rpm - ANSWER-An elevators motor rotates at 1200 rpm at contract speed and is geard at a ratio of 40:1. If the motor turns 40 rpm the sheave turns 1 rpm. What is the actual speed of the drive sheave in rpms? The output will go to zero - ANSWER-Refer to figure 2. For the comparator circuit shown, what will happen to the output of the non-inverting input goes more positive than the inverting input? -20 mv - ANSWER-Refer to figure 3. For the inverting op amp shown, what is the output voltage? Saturation - ANSWER-Which term defines the limit of magnetic strength around an inductor even though the current through the coil increases Voltage is removed from anode to cathode - ANSWER-Which of the following describes how an SCR is turned OFF? Top right - ANSWER-On the fourteen pin DIP IC shown in figure 4 what is the location of pin 14 1507 ohms - ANSWER-A brake coil has an inductance of 4 henries. If the coil was placed into a circuit with an operating frequency of 60hz the coil would have a resistance of: light - ANSWER-The photodiode will conduct current when it detects A relay timer - ANSWER-What does the circuit in figure 5 represent? 12.5 A - ANSWER-A string of temporary lighting has fifteen 100 watt bulbs. A 15 amp breaker is the maximum size that can be used with the 14 gauge wire used in this 120 volt circuit. What is the current? 4.61 henries - ANSWER-If a circuit has three inductors in parallel of 10, 15, and 20 henries, what is the total inductance? LED - ANSWER-What does the symbol in figure 6 represent? A .7V drop from base-to-emitter is an indication of a good junction - ANSWER-Which of the following statements is correct when testing transistors? An SCR - ANSWER-What does the symbol shown below represent? 5 seconds - ANSWER-What is the length of time required to charge a 500-microfarad capacitor in series with a 10K ohm resistor to the maximum applied voltage of 125 VDC? (TC = R x C) It is nearly equal to the emitter current - ANSWER-Which of the following is correct about collector current of a transistor? 4400 pounds - ANSWER-The entire cab assembly, including the car sling, cab doors, operator, etc., weighs 3400 lbs. The capacity of the elevator is 2500 lbs. The car must be counterweighted at 40% of capacity plus the weight of the car assembly. What is the weight of the counterweight assembly? The ability to resist changes in current flow - ANSWER-What is the most important property an inductor possesses? Placing two capacitors in series decreases the capacitance. - ANSWER-Which statement is correct regarding capacitors? Dielectric - ANSWER-Which of the following factors determines the voltage rating of a capacitor? A resistor is placed in series with the capacitor - ANSWER-What is usually done to protect large capacitors during charging? Excessive current in the coil circuit - ANSWER-An MOV placed around a relay coil for voltage spike suppression has shorted. What would the effects be? They may be polarity sensitive - ANSWER-Which of the following do you need to be aware of when using electrolytic capacitors? A low (0) on input A and a high (1) on input B - ANSWER-Refer to figure 7. What inputs are necessary to get a low (0) on the output?