Login or Register for FREE!
Subelement C
Components
Section 19
Photoconductive Devices
What happens to the conductivity of photoconductive material when light shines on it?
  • Correct Answer
    It increases.
  • It decreases.
  • It stays the same.
  • It becomes temperature dependent.
This question does not yet have an explanation! Register to add one

Tags: none

What is the photoconductive effect?
  • The conversion of photon energy to electromotive energy.
  • Correct Answer
    The increased conductivity of an illuminated semiconductor junction.
  • The conversion of electromotive energy to photon energy.
  • The decreased conductivity of an illuminated semiconductor junction.
This question does not yet have an explanation! Register to add one

Tags: none

What does the photoconductive effect in crystalline solids produce a noticeable change in?
  • The capacitance of the solid.
  • The inductance of the solid.
  • The specific gravity of the solid.
  • Correct Answer
    The resistance of the solid.
This question does not yet have an explanation! Register to add one

Tags: none

What is the description of an optoisolator?
  • Correct Answer
    An LED and a photosensitive device.
  • A P-N junction that develops an excess positive charge when exposed to light.
  • An LED and a capacitor.
  • An LED and a lithium battery cell.
This question does not yet have an explanation! Register to add one

Tags: none

What happens to the conductivity of a photosensitive semiconductor junction when it is illuminated?
  • The junction resistance is unchanged.
  • Correct Answer
    The junction resistance decreases.
  • The junction resistance becomes temperature dependent.
  • The junction resistance increases

Standard semiconductors use voltage at the base to control the conductivity of the junction a photosensitive semiconductor uses light instead.

As the light increases the junction resistance decreases therefore increasing the conductivity.

Last edited by erik walter. Register to edit

Tags: none

What is the description of an optocoupler?
  • A resistor and a capacitor.
  • Two light sources modulated onto a mirrored surface.
  • Correct Answer
    An LED and a photosensitive device.
  • An amplitude modulated beam encoder.
This question does not yet have an explanation! Register to add one

Tags: none

Go to 18 Go to 29