600 Final Review Neiep

600 Final Review Neiep Questions And Answers -20 mv - Refer to figure 3. For the inverting op amp shown, what is the output voltage? 0.3 - The voltage required to cause conduction across the junction in a germanium diode is? 0.3 seconds - What is the time constant for a circuit with 150 K ohms and 2 microfarad capacitor? (TC = R x C) 1.5 seconds - How long will it take for this capacitor to be considered fully charged? 2-50uf/300VDC capacitors in parallel - What combination of capacitors could be used to replace a 100uf/250 VDC capacitor? 2.4 A - The secondary load current of a 2300 to 120 volt transformer is 46 amperes. What is the current primary? (E = I x R) 3k ohms - A 1.5 volt 8 milliamp light emitting diode needs to be operated from a 24VDC circuit. What series resistance is required? 4 - How many rectifier diodes are required to make a full wave bridge rectifier? 4.61 henries - If a circuit has three inductors in parallel of 10, 15, and 20 henries, what is the total inductance? 4v - 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 5 seconds - 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) 5AD - What is the hexadecimal equivalent of 12.5 A - 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? 30 rpm - 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? 169.7 VAC - What is the peak value of an AC voltage whose RMS value is 120 volts? 190 VDC - What is the correct average output voltage for a full-wave bridge rectified using silicon diodes with a peak input supply voltage of 300 VAC 350uf/150VDC - What is the total capacitance and the maximum applied voltage for the circuit in figure 8? - What is the binary equivalent of 131 10? 1507 ohms - 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: 4400 pounds - 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? A .7V drop from base-to-emitter is an indication of a good junction - Which of the following statements is correct when testing transistors? A high (1) on input A and B - Refer to figure 9. What inputs are necessary to get a high (1) on the output? A low (0) on input A and a high (1) on input B - Refer to figure 7. What inputs are necessary to get a low (0) on the output? A relay timer - What does the circuit in figure 5 represent? A resistor is placed in series with the capacitor - What is usually done to protect large capacitors during charging? An SCR - What does the symbol shown below represent? Anode positive, cathode negative, gate pulse positive - Which of the following statements is correct for properly biasing an SCR to turn ON? Capacitor voltage is minimum and current is maximum - Which of the following statements is correct when DC is first applied in an RC circuit? Dielectric - Which of the following factors determines the voltage rating of a capacitor? Excessive current in the coil circuit - An MOV placed around a relay coil for voltage spike suppression has shorted. What would the effects be? It is an opposing force to the applied voltage which resists changes in circuit current - What effect does counter electromotive force (CEMF) h