chapter 10 Flashcards
A forward biased diode that releases light energy is called a(n) ? .
light-emitting diode (LED)
An optoelectronic device that emits light of one frequency or color is called a(n) ? .
laser diode
What is the proper name for a diode that emits infrared light when forward biased?
IRED
The forward voltage drop of light-emitting diodes and infrared-emitting diodes is the same as the forward voltage drop for silicon diodes.
false
The forward voltage drop of light-emitting diodes and infrared-emitting diodes is greater than the forward voltage drop for silicon diodes.
A seven-segment display is an arrangement of seven light emitting diodes used to display numbers 0 through 9.
true
What type of diode is sensitive to light and exhibits less internal bias in the reverse bias mode when exposed to a light source?
photodiode
A(n) ? is a device that is made up of two separate devices—an LED and a light-sensing diode, or photodiode.
optocoupler
What size resistor will be required to connect an LED with 1.8-volt forward drop to a 24-volt DC power supply? (Assume 20-milliamp current.)
1110 ohms
What would be the recommended wattage value for the resistor in the previous question? (Use a safety factor of 2 and round the answer up to the nearest quarter watt.)
1 w
Photodiodes in photoconductive mode are normally operated in forward bias.
false
A phototransistor is more sensitive to light than a photodarlington.
false
Which light sensitive device could be used to switch AC current?
Phototriac
The primary function of a(n) ? is to provide electrical separation between input and output signals.
optoisolator
Which of the following is not an advantage of fiber optic cable over conventional copper cable?
Smaller data capacity for long runs
An optoelectronic device that emits monochromatic light is called a ? .
laser diode
The principle of operation of fiber optic cable is total internal reflection of light.
true
Light strikes a transparent surface and divides into a reflected beam and a refracted, or bent, beam.
true
When light strikes a transparent surface at less than the critical angle, the light is reflected.
false
Which of the following is a configuration for fiber optic cable that is associated with the path the light takes through the cable?
Graded-index multimode fiber Incorrect
Single-mode fiber Incorrect
Step-index multimode fiber
Which type of fiber is best suited for long distance high speed data applications?
Single-mode fiber
Fiber optic cables used for data transmission typically carry light signals at levels ? or less.
100 µW
Which of the following parts are used to make up a fiber optic cable?
Buffer jacket
Cladding
Core
Outer jacket or protective sheath
Silicon coating
Strength member
