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

1. A Protons
2. B Photons
3. C Electrons
4. D Holes

What happens to photoconductive material when light shines on it?

1. A Resistance decreases
2. B Resistance increases
3. C Reflectivity increases
4. D Reflectivity decreases

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

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

What is the photovoltaic effect?

1. A The conversion of voltage to current when exposed to light
2. B The conversion of light to electrical energy
3. C The effect that causes a photodiode to emit light when a voltage is applied
4. D The effect that causes a phototransistor's beta to decrease when exposed to light

Which of the following describes an optical shaft encoder?

1. A A device that detects rotation by interrupting a light source with a patterned wheel
2. B A device that measures the strength of a beam of light using analog-to-digital conversion
3. C An optical computing device in which light is coupled between devices by fiber optics
4. D 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 Polyphenol acetate
2. B Argon
3. C Crystalline semiconductor
4. D All these choices are correct

What is a solid-state relay?

1. A A relay that uses transistors to drive the relay coil
2. B A device that uses semiconductors to implement the functions of an electromechanical relay
3. C A mechanical relay that latches in the on or off state each time it is pulsed
4. D A semiconductor switch that uses a monostable multivibrator circuit

Why are optoisolators often used in conjunction with solid-state circuits that control 120 VAC circuits?

1. A Optoisolators provide a low-impedance link between a control circuit and a power circuit
2. B Optoisolators provide impedance matching between the control circuit and power circuit
3. C Optoisolators provide an electrical isolation between a control circuit and the circuit being switched
4. D Optoisolators eliminate the effects of reflected light in the control circuit

What is the efficiency of a photovoltaic cell?

1. A The output RF power divided by the input DC power
2. B The output in lumens divided by the input power in watts
3. C The open-circuit voltage divided by the short-circuit current under full illumination
4. D The relative fraction of light that is converted to current

What is the most common material used in power-generating photovoltaic cells?

1. A Selenium
2. B Silicon
3. C Cadmium sulfide
4. D Indium arsenide

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

1. A 0.5 volts
2. B 0.7 volts
3. C 1.1 volts
4. D 1.5 volts