Practice Test Geeks(CET) Certified Electronics Technician Practice Test
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Electronic Components and Devices Flashcards

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

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  1. What is the primary difference between enhancement and depletion mode MOSFETs?

    Answer: Depletion mode devices have a pre-existing channel at VGS=0; enhancement mode do not

    Depletion mode MOSFETs have a physical channel formed at VGS=0 and can be depleted or enhanced; enhancement mode MOSFETs require gate voltage to induce a channel.

  2. Which diode is specifically designed for low forward voltage drop and fast switching in high-frequency circuits?

    Answer: Schottky diode

    The Schottky diode uses a metal-semiconductor junction with a forward drop of ~0.2–0.3 V and no minority carrier storage, enabling fast switching.

  3. When two capacitors of 10 µF and 40 µF are connected in series, what is the total capacitance?

    Answer: 8 µF

    For series capacitors: 1/C_total = 1/10 + 1/40 = 5/40, so C_total = 8 µF.

  4. In a full-wave bridge rectifier with a peak input voltage of 20 V, what is the approximate DC output voltage (ignoring diode drops)?

    Answer: 12.73 V

    The average DC output of a full-wave rectifier is Vpeak × (2/π) = 20 × 0.637 ≈ 12.73 V.

  5. Which component is used to suppress voltage spikes (transients) across an inductive load such as a relay coil?

    Answer: Freewheeling (flyback) diode

    A freewheeling diode placed antiparallel to the inductive load provides a path for the inductive current when the switch opens, preventing high-voltage spikes.

  6. The Early effect in a BJT refers to:

    Answer: Variation of collector current with collector-emitter voltage due to base width modulation

    The Early effect describes the slight increase in collector current as VCE increases, caused by the depletion region narrowing the effective base width.

  7. A UJT (Unijunction Transistor) is primarily used in which type of application?

    Answer: Relaxation oscillators and timing circuits

    The UJT's negative resistance region makes it ideal for generating sawtooth waveforms in relaxation oscillators and triggering SCR/TRIAC circuits.