Practice Test Geeks(CET) Certified Electronics Technician Practice Test
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CET Power Supplies and Electrical Safety Flashcards

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

Read the first 6 CET Power Supplies and Electrical Safety flashcards as text

  1. What current level through the human body is generally considered the threshold for causing ventricular fibrillation?

    Answer: 100 mA

    Approximately 100 mA through the chest region for more than a fraction of a second can induce ventricular fibrillation, which is fatal without defibrillation.

  2. What does a Ground Fault Circuit Interrupter (GFCI) outlet protect against?

    Answer: Electric shock from current leaking to ground through a person

    A GFCI monitors the difference between hot and neutral currents; if more than ~5 mA is unaccounted for (leaking through a person), it trips within milliseconds.

  3. What is the function of a Metal Oxide Varistor (MOV) in a surge protector?

    Answer: Clamp transient overvoltages by conducting heavily when voltage exceeds a threshold

    An MOV has a highly non-linear resistance that drops sharply at its clamping voltage, diverting surge energy away from protected equipment.

  4. What IEC safety class designates equipment with double insulation that requires no protective earth ground connection?

    Answer: Class II

    IEC Class II equipment uses double or reinforced insulation and bears the square-within-a-square symbol; no earth ground pin is needed.

  5. Why are bleeder resistors used in high-voltage power supply circuits?

    Answer: Discharge filter capacitors when power is removed, preventing electric shock

    Bleeder resistors provide a discharge path for stored capacitor charge so the output voltage decays to a safe level when the supply is turned off.

  6. Which grounding method bonds the equipment chassis to earth ground to protect a user from electric shock if an internal fault energizes the chassis?

    Answer: Protective earth grounding

    Protective earth grounding connects the chassis to earth so a fault current flows to ground and trips the breaker rather than passing through the user.