Description : What phenomenon will result if the glass fiber is exposed to long periods of high humidity? ∙ A. stress fatigue ∙ B. core corrosion ∙ C. stress corrosion ∙ D. cladding corrosion
Last Answer : stress corrosion
Description : The maximum angle in which external light rays may strike the air/glass interface and still propagate down the fiber.
Last Answer : Acceptance cone half-angle
Description : It is a result of photons of light that are absorbed by the atoms of the glass core molecule
Last Answer : infrared absorption
Description : It is caused by valence electrons in the silica material from which the fiber are manufactured.
Last Answer : ultraviolet absorption
Description : It is analogous to power dissipation to copper cables, impurities in the fiber absorb the light and covert it to heaT
Last Answer : absorption loss
Description : Developed an optical fiber with losses less that 2 dB/km
Last Answer : Kao and Bockham
Description : A popular light wavelength fiber-optic cable is
Last Answer : 1.3 micrometer
Description : A single fiber can handle as many voice channels as.
Last Answer : a 1500-pair cable The term power budgeting refers to: Ans. the total power available minus the attenuation losses
Description : Which type of fiber-optic cable is the most widely used?
Last Answer : multimode step-index
Description : Which type of fiber-optic cable has the least modal dispersion?
Last Answer : single-mode step index
Description : These bends are caused by excessive pressure and tension and generally occur while fiber are bent during handling or installation.
Last Answer : constant-radius bending
Description : They were granted patents for scanning and transmitting television images through uncoated fiber cables
Last Answer : Baird and Hansel
Description : They proposed a new communication medium using cladded fiber cables.
Description : He coined the term “fiber optics” in 1956.
Last Answer : Kapany
Description : Approximately what is the frequency limit of the optical fiber?
Last Answer : 40 GHz
Description : _______ is a standard developed by ANSI for fiber-optic networks.
Last Answer : SONET
Description : The result whenever the sampling rate is less than twice the highest audio frequency.
Last Answer : alias
Description : What is the result if the input of ADC is changing while performing conversion? A
Last Answer : Aperture distortion
Description : Type of bend that occurs as a result of differences in thermal contraction rates between the core and the cladding material.
Last Answer : Microbending
Description : A special type of transmission line that consist of conducting metallic tube through which high frequency electromagnetic energy is propagated
Last Answer : waveguide
Description : What circuit in the TV receiver is used to develop the high voltage needed to operate the picture tube?
Last Answer : Horizontal output
Description : “When visible light of high frequency electromagnetic radiation illuminates a metallic surface, electrons are emitted”
Last Answer : Plank’s law
Description : How long does it take to scan 2 picture elements when 400 are scanned in 50 microseconds?
Last Answer : 0.25 microsec
Description : Wet-bulb temperature is: a. The temperature indicated by a thermometer whose bulb covered by a water-wetted wick and exposed to a rapidly moving stream of air b. The same as the dry-bulb ... point temperature d. Always less than the dry-bulb temperature e. Not required to find the relative humidity
Last Answer : Answer: A
Description : The cooling effect in a cooling tower can be speeded up by (A) Increasing the air velocity and area of exposed wet surface (B) Reducing the barometric pressure (C) Reducing the humidity of the air (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Evaporation from water surfaces exposed to air is not dependent of the: w) velocity of the wind x) humidity y) temperature z) depth of the water
Last Answer : ANSWER: Z -- DEPTH OF THE WATER
Description : A commutator's protective oxide film can be destroyed by _________________. A. periods of low humidity B. very low brush current density C. improper brush grade D. all of the above
Last Answer : Answer: D
Description : The magnetic field of an antenna is perpendicular to the earth. The antenna’s polarization ___
Last Answer : is horizontal
Description : It is the ratio of the power density radiated in a particular direction to the power density radiated to the same point by a reference antenna, assuming both antennas are radiating the same amount of power
Last Answer : directive gain
Description : The property of interchangeability for the transmitting and receiving operations is known as ____
Last Answer : reciprocity
Description : The fields surrounding the antenna do not collapse their energy back into the antenna but rather radiate it out in space
Last Answer : radiation field
Description : It is the ratio of the radiated to the reflected energy:
Last Answer : Radiation efficiency
Description : It is the resistance that, if it replaced the antenna, would dissipate exactly the same amount of power that the antenna radiates
Last Answer : . Radiation resistance
Description : Plots of field strength or power density with respect to the value at a reference point.
Last Answer : relative radiation pattern
Description : The radiation pattern plotted in terms of electric field strength or power density
Last Answer : absolute radiation pattern
Description : The line bisecting the major lobe, or pointing from the center of the antenna in the direction of maximum radiation is called _____
Last Answer : line of shoot
Description : If energy is applied at the geometrical center of antenna, the antenna is said to be ___
Last Answer : center-fed
Description : The radiation pattern of collinear and a broadside antenna is __
Last Answer : bidirectional
Description : Hertz antenna are predominantly used with frequencies above
Last Answer : 2MHz
Description : The point on the antenna where the transmission line is connected is called _____
Last Answer : feedpoint
Description : The discone antenna is
Last Answer : useful as a UHF receiving antenna
Description : It is the same with directive gain except that the total power fed to the antenna is used and the antenna efficiency is taken into account.
Last Answer : power gain
Description : ____ is a process-to-process protocol that adds only port addresses, checksum error control, and length information to the data from the upper layer.
Last Answer : UDP
Description : ______ are special-interest groups that quickly test, evaluate, and standardize new technologies
Last Answer : Forums
Description : _______ refers to the structure or format of the data, meaning the order in which they are presented.
Last Answer : Semantics
Description : ________ defines how a particular pattern to be interpreted, and what action is to be taken based on that interpretation.
Last Answer : syntax
Description : The effect of a large magnitude of the numerical aperture.
Last Answer : The amount of external light the fiber will accept is greater
Description : It is the figure of merit used to measure the magnitude of the acceptance angle.
Last Answer : numerical aperture
Description : Laser light is very bright because it is:
Last Answer : coherent