ASVAB (Armed Services Vocational Aptitude Battery)Electronics Information (EI)Easy

A technician is testing a diode in a circuit. Using a multimeter, they measure a voltage drop of approximately 0.7V across the diode when it is forward-biased and a very high resistance when it is reverse-biased. What type of diode is most likely being tested?

  1. AGermanium diode
  2. BSilicon diode
  3. CLight-Emitting Diode (LED)
  4. DZener diode
Show answer & explanation

Correct answer: B. Silicon diode

A silicon diode typically has a forward voltage drop of approximately 0.7V, which is a key characteristic for identifying it. Germanium diodes have a lower forward voltage drop, while Zener diodes are designed for reverse-bias breakdown, and LEDs emit light.

Why the other options are wrong

  • A. Germanium diodes have a lower forward voltage drop, typically around 0.3V.
  • C. LEDs are designed to emit light and have varying forward voltage drops depending on color.
  • D. Zener diodes are designed to operate in reverse breakdown, maintaining a stable voltage.

Silicon Diode

A semiconductor device made from silicon that allows current to flow primarily in one direction, characterized by a forward voltage drop of approximately 0.7V.

  • Made from silicon semiconductor material.
  • Allows current flow in one direction (forward bias).
  • Requires approximately 0.7V to turn on (forward voltage drop).

Memory trick: Diode's Direction Determines Drop.

More Electronics Information (EI) questions