E6F: Optical components and power systems: photoconductive principles and effects, photovoltaic systems, optical couplers, optical sensors, and optoisolators
E6F01:
What is photoconductivity?
The increased conductivity of an illuminated semiconductor
The conversion of photon energy to electromotive energy
The conversion of electromotive energy to photon energy
The decreased conductivity of an illuminated semiconductor
E6F02:
What happens to the conductivity of a photoconductive material when light shines on it?
It increases
It decreases
It stays the same
It becomes unstable
E6F03:
What is the most common configuration for an optocoupler?
An LED and a phototransistor
A lens and a photomultiplier
A frequency modulated helium-neon laser
An amplitude modulated helium-neon laser
E6F04:
Which of the following is an optoisolator?
An LED and a phototransistor
A P-N junction that develops an excess positive charge when exposed to light
An LED and a capacitor
A P-N junction that develops an excess negative charge when exposed to light
E6F05:
What is an optical shaft encoder?
An array of optocouplers whose light transmission path is controlled by a rotating wheel
An array of neon or LED indicators whose light transmission path is controlled by a rotating wheel
An array of neon or LED indicators mounted on a rotating wheel in a coded pattern
An array of optocouplers mounted on a rotating wheel in a coded pattern
E6F06:
What characteristic of a crystalline solid will photoconductivity change?
The resistance
The capacitance
The inductance
The specific gravity
E6F07:
Which material will exhibit the greatest photoconductive effect when illuminated by visible light?
Cadmium sulfide
Potassium nitrate
Lead sulfide
Sodium chloride
E6F08:
Which material will exhibit the greatest photoconductive effect when illuminated by infrared light?
Lead sulfide
Potassium nitrate
Cadmium sulfide
Sodium chloride
E6F09:
Which of the following materials is affected the most by photoconductivity?
A crystalline semiconductor
An ordinary metal
A heavy metal
A liquid semiconductor
E6F10:
What characteristic of optoisolators is often used in power supplies?
They have very high impedance between the light source and the phototransistor
They have low impedance between the light source and the phototransistor
They have low impedance between the light source and the LED
They have very high impedance between the light source and the LED
E6F11:
What characteristic of optoisolators makes them suitable for use with a triac to form the solid-state equivalent of a mechanical relay for a 120 V AC household circuit?
Optoisolators provide a very high degree of electrical isolation between a control circuit and a power circuit
Optoisolators provide a low impedance link between a control circuit and a power circuit
Optoisolators provide impedance matching between the control circuit and power circuit
Optoisolators eliminate (isolate) the effects of reflected light in the control circuit
E6F12:
Which of the following types of photovoltaic cell has the highest efficiency?
Gallium arsenide
Silicon
Silver iodide
Selenium
E6F13:
What is the most common type of photovoltaic cell used for electrical power generation?
Silicon
Selenium
Cadmium Sulfide
Copper oxide
E6F14:
Which of the following is the approximate open-circuit voltage produced by a fully-illuminated silicon photovoltaic cell?
0.5 V
0.1 V
1.5 V
12 V
E6F15:
What absorbs the energy from light falling on a photovoltaic cell?
Electrons
Protons
Photons
Holes
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