Practice Test Geeks(ITMC) Industrial Technology Maintenance Certification Practice Test
← All ITMC Flashcard Decks

Electrical & Electronic Systems Flashcards

7 cards from real ITMC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Electrical & Electronic Systems flashcards as text

  1. A three-phase motor draws 18A per phase at 480V. What is the approximate total power consumption?

    Answer: 14,968 W

    Three-phase power = √3 × V × I = 1.732 × 480 × 18 ≈ 14,968 W.

  2. Which type of capacitor is commonly used for power factor correction in industrial motor circuits?

    Answer: Run capacitor (oil-filled)

    Oil-filled run capacitors are designed for continuous AC duty and are the standard choice for industrial power factor correction.

  3. When troubleshooting a PLC input module, the indicator LED is ON but the program logic shows the input as OFF. The most likely cause is:

    Answer: Failed input module optocoupler

    If the LED lights (indicating voltage at the terminal) but the PLC reads OFF, the optocoupler inside the input module has failed to pass the signal.

  4. An insulation resistance test on a 480V motor winding reads 0.8 MΩ. What action should be taken?

    Answer: Motor should be removed from service for rewinding or drying

    IEEE 43 recommends a minimum of 1 MΩ for motors operating below 1 kV; 0.8 MΩ falls below this threshold and warrants removal from service.

  5. Which wiring method provides the best protection against electromagnetic interference (EMI) in a signal cable?

    Answer: Twisted pair with overall shield grounded at one end

    Twisted pair cancels magnetically induced noise while a shield grounded at one end prevents ground loops and blocks electric field interference.

  6. A 24VDC control relay coil measures infinite resistance with an ohmmeter. This indicates:

    Answer: The coil winding is open (broken)

    An infinite (OL) resistance reading across a coil means the wire inside has broken, creating an open circuit.

  7. What is the purpose of a snubber circuit connected across a relay coil or motor contactor?

    Answer: Suppress voltage transients caused by inductive kickback

    When an inductive coil is de-energized, the collapsing magnetic field produces a voltage spike; snubbers (RC networks or MOVs) clamp these transients to protect switching devices.