Practice Test Geeks(ISCET) International Society of Certified Electronics Technicians Practice Test
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Test Equipment Operation & Troubleshooting Flashcards

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

Read the first 7 Test Equipment Operation & Troubleshooting flashcards as text

  1. A technician observes that a sine wave on an oscilloscope has a flat top (clipping). This MOST likely indicates:

    Answer: The amplifier stage is saturating or the scope input is overdriven

    Flat-topped (clipped) sine waves indicate that an amplifier is being driven into saturation or that the oscilloscope input is overloaded beyond its dynamic range.

  2. Which instrument is used to measure the total harmonic distortion (THD) of an audio amplifier output?

    Answer: Distortion analyzer or spectrum analyzer

    A distortion analyzer or spectrum analyzer measures the ratio of harmonic energy to the fundamental frequency energy, yielding the THD percentage.

  3. When measuring a transistor's beta (hFE) with a DMM in transistor test mode, the reading is 0. This indicates:

    Answer: The transistor's base-emitter junction is open or the device is faulty

    A beta reading of 0 indicates the transistor cannot amplify current, pointing to an open base-emitter junction or a completely failed device.

  4. What does it mean when a logic probe LED remains continuously lit (not pulsing) on a digital circuit node?

    Answer: The node is stuck at a constant HIGH logic level

    A continuously lit LED on a logic probe indicates the node is held at a constant HIGH logic state rather than toggling.

  5. A technician is measuring AC voltage at 60 Hz with a DMM set to DC volts by mistake. The expected reading is:

    Answer: Near zero volts due to averaging of the AC waveform

    A DMM set to DC mode averages the input signal; a symmetrical AC sine wave averages to near zero over a full cycle.

  6. Which precaution is MOST important when using a megohmmeter (megger) to test insulation resistance?

    Answer: Discharge the equipment under test before and after the megger test

    A megohmmeter applies high DC voltage (typically 500–1000 V) that can charge capacitance in the equipment; the equipment must be discharged before and after the test to prevent shock hazards.

  7. On a dual-trace oscilloscope set to ALTernate mode, both channels are displayed by:

    Answer: Alternating between channel 1 and channel 2 on successive sweeps

    In ALT mode, the oscilloscope displays channel 1 on one sweep and channel 2 on the next sweep, which works well at higher frequencies.