Industrial Red Seal Practice Exam - Question and correct Answers

Industrial Red Seal Practice Exam - Question and correct Answers If the three dark lamp method of synchronizing alternators is being used and you find that the lights are all going dark at different times the problem is incorrect: A) frequency. B) phase sequence. C) phase position. D) terminal voltage. The staring torque of a single-phase capacitor start motor is higher than that of a single-phase resistance start motor because it has: A) greater displacement between its start and main winding currents. B) less displacement between start and main winding currents. C) no displacement between start and main winding currents. D) a higher power factor. The output voltage of a DC generator is normally controlled by varying the: A) load. B) number of armature conductors. C) field current. D) rotational speed. The _______ of a DC machine support the bearings. A) armature B) yoke C) brushes D) end bells Torque in a motor is developed by: A) the motor shell B) the end bells C) the rotor D) the rotor bearings A synchronous motor has a higher efficiency than an induction motor in part due to: A) salient poles. B) field excitation. C) reduced vibration. D) unity power factor armature current. When the no load and full load speed of a DC motor is 1100 r/min and 825 r/min respectively, the motor will be operating at ______ percent speed regulation. A) 25.0 B) 33.3 C) 75.0 D) 91.7 The speed regulation of a three-phase 60 Hz, six pole induction motor with a no-load speed of 1175 rpm and a 3.0 percent slip at full-load is: A) 1.5% B) .95% C) 50% D) 35% The VFD must supply a voltage to the motor that is: A) alternating B) directly proportional to the frequency C) inversely proportional to the frequency D) inversely proportional to the load The letters UPS stand for: A) uninterruptible positive supply B) united proton supply C) uninterruptible proton system D) uninterruptible power supply The input power to a VFD controlling a three-phase squirrel cage induction motor could be single-phase. A) True B) False The voltage of a circuit is regulated by a zener shunt regulator of the following specifications. Supply = 40 Volts dc Series resistor = 125 ohms Zener diode = 12 Volt Load = 550 ohms. Calculate the current through the load: A) 193 milliamps B) 215 milliamps C) 21.8 milliamps D) 308 milliamps When the rotor of a squirrel cage induction motor starts to accelerate, the rotor EMF increases. A) True B) False How should you verify that the bus capacitors of a VFD are discharged? A) With an AC voltmeter B) With a DC voltmeter C) With an Ammeter D) With an Ohmmeter The main disadvantage of star topology is that it provides a central location for managing the network and makes it difficult to locate and isolate faults. A) True B) False What is the maximum recommended distance, in meters, for 100 ohm UTP cable for data installations? A) 300 B) 200 C) 150 D) 90 Why are door mounted magnetic reed switches popular? A) They require no wires. B) They are inexpensive to buy. C) They can handle high ambient temperatures. D) The sound amplification is excellent. The interconnect series cable is a tight buffer copper cable that is specifically designed for low fibre count, intra building conditions where the networking application involves high volume on site terminations A) True B) False Where must smoke alarms be installed in a residential occupancy? A) In all bathrooms. B) In all bedrooms. C) In all kitchens. D) On each level of a house. What cause the majority of the fire related deaths? A) water B) smoke C) heat Ten seconds after the start button is pushed and M1 has been energized: A) M1 will de-energize. B) M2 will energize. C) M3 will energize. D) M2 will de-energize. Refer to the information in question 83. Referring to the above diagram, when M1 has been energized for 6 seconds: A) M2 and TR2 are energized. B) everything will de-energized. C) all timing relays are energized. D) M1 holding contacts will be closed and TR1 is energized. Refer to the information in question 83. Once the start button has been pushed the circuit will go through its timing cycle and everything will de-energise after _____ seconds. A) 60 B) 70 C) 80 D) 90 To modify a systems operation without the use of a PLC many control systems require ________ changes. A) very minor B) hard wiring C) software program D) higher voltage A PLC control system provides a cost advantage of: A) cheaper hardware. B) cheaper software. C) less hard wiring. D) fewer external control relays. D One of the main advantages to using a PLC is: A) it reduces the amount of control wires used. B) there is no need for wiring stop and start buttons. C) the PLC replaces magnetic starters. D) it can be easily reprogrammed if requirements change. D PLCs