What absorbs the energy from light falling on a photovoltaic cell?

  1. Protons
  2. Photons
  3. Electrons
  4. Holes


What happens to the conductivity of a photoconductive material when light shines on it?

  1. It increases
  2. It decreases
  3. It stays the same
  4. It becomes unstable


What is the most common configuration of an optoisolator or optocoupler?

  1. A lens and a photomultiplier
  2. A frequency modulated helium-neon laser
  3. An amplitude modulated helium-neon laser
  4. An LED and a phototransistor


What is the photovoltaic effect?

  1. The conversion of voltage to current when exposed to light
  2. The conversion of light to electrical energy
  3. The conversion of electrical energy to mechanical energy
  4. The tendency of a battery to discharge when exposed to light


Which describes an optical shaft encoder?

  1. A device that detects rotation of a control by interrupting a light source with a patterned wheel
  2. A device that measures the strength of a beam of light using analog to digital conversion
  3. A digital encryption device often used to encrypt spacecraft control signals
  4. A device for generating RTTY signals by means of a rotating light source


Which of these materials is most commonly used to create photoconductive devices?

  1. A crystalline semiconductor
  2. An ordinary metal
  3. A heavy metal
  4. A liquid semiconductor


What is a solid-state relay?

  1. A relay using transistors to drive the relay coil
  2. A device that uses semiconductors to implement the functions of an electromechanical relay
  3. A mechanical relay that latches in the on or off state each time it is pulsed
  4. A semiconductor passive delay line


Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

  1. Optoisolators provide a low impedance link between a control circuit and a power circuit
  2. Optoisolators provide impedance matching between the control circuit and power circuit
  3. Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
  4. Optoisolators eliminate the effects of reflected light in the control circuit


What is the efficiency of a photovoltaic cell?

  1. The output RF power divided by the input DC power
  2. Cost per kilowatt-hour generated
  3. The open-circuit voltage divided by the short-circuit current under full illumination
  4. The relative fraction of light that is converted to current


What is the most common type of photovoltaic cell used for electrical power generation?

  1. Selenium
  2. Silicon
  3. Cadmium Sulfide
  4. Copper oxide


What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

  1. 0.1 V
  2. 0.5 V
  3. 1.5 V
  4. 12 V