Description : In a waveguide, what is a frequency that would cause angles of incidence and reflection to be zero degrees?
Last Answer : Critical Frequency
Description : The size, shape, and dielectric material of a waveguide must be constant throughout its length for energy to move from one end to the other without reflections. What could be the effect in any abrupt change in its size or shape?
Last Answer : Reflections.
Description : What device can be constructed to allow microwave energy to pass in one direction but blocks energy in the other direction in a waveguide?
Last Answer : errite Isolato
Description : What is a device that provides a method of sampling energy from within a waveguide for measurement or use in another circuit?
Last Answer : Directional Coupler
Description : When electromagnetic wave are propagated through a waveguide, they A. are reflected from the walls but do not travel along them B. travel along all four walls of the waveguide C. travel along the broader walls of the guide D. travel through the dielectric without touching the walls
Last Answer : A. are reflected from the walls but do not travel along them
Description : What term is used to identify the forward progress velocity of wavefronts in a waveguide?
Last Answer : Group velocity.
Description : A waveguide may also be terminated in a resistive load that is matched to the characteristic impedance of the waveguide. The resistive load is most often called a _____
Last Answer : Dummy resistor
Description : What travels down a waveguide by reflecting from the side walls in a zigzag pattern?
Last Answer : wavefronts
Description : It is the ratio of the radiated to the reflected energy:
Last Answer : Radiation efficiency
Description : Standing waves are formed when two sets of waves of equal amplitude and frequency w) are in phase x) are in opposite phase y) move through each other in opposite directions z) are reflected from the same surface
Last Answer : ANSWER: Y -- MOVE THROUGH EACH OTHER IN OPPOSITE DIRECTIONS
Description : How is the cutoff wavelength of a circular waveguide figured?
Last Answer : 1.71 times the diameter.
Description : .Diffractionof electromagneticwaves a. is caused by reflections from the ground b. arises only with spherical wavefronts c. will occur when the waves pass through a large slot d.may occuraroundthe edge of asharpobstacle
Last Answer : d.may occuraroundthe edge of asharpobstacle
Description : As EM waves travel in free space they get:
Last Answer : attenuated
Description : They wrote a paper describing how it was possible to use stimulated emission for amplifying light waves (laser) as well as microwaves (maser).
Last Answer : Charles Townes and Arthur Schawlow
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 : When microwave energy is passed through a piece of ferrite in a magnetic field, another effect occurs. If the frequency of the microwave energy is much greater than the electron wobble frequency, the plane of polarization of the wavefront is rotated. This is known as
Last Answer : Faraday Rotation Effect
Description : All Waves A. Have troughs and nodes B. Move back and forth C. Transfer energy D. are big
Last Answer : A. Have troughs and nodes
Description : The time it takes a light induced carrier travel across the depletion region of the semiconductor.
Last Answer : . transit time
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 : In changing the frequency of a cavity, what is accomplished by placing a nonmagnetic slug in the area of maximum H lines
Last Answer : Inductive Coupling
Description : The vertical field-scanning frequency is ______ Hz
Last Answer : 60
Description : In the Philippine color television system, the intercarrier frequency, in MHz, is
Last Answer : 4.5
Description : Which circuit is most common to both frequency-hopping and direct-sequence spread spectrum transmitters?
Last Answer : PSN code generator
Description : The result whenever the sampling rate is less than twice the highest audio frequency.
Last Answer : alias
Description : An FDM hierarchy which is formed by frequency – division multiplexing 10 super groups together for a combined capacity of 600 voice band message channels.
Last Answer : Mastergroup
Description : An FDM hierarchy which is formed by frequency – division multiplexing five groups containing 12 channels each for a combined bandwidth of 240 kHz
Last Answer : Supergroup
Description : “When visible light of high frequency electromagnetic radiation illuminates a metallic surface, electrons are emitted”
Last Answer : Plank’s law
Description : What is the frequency limit of a copper wire?
Last Answer : approximately 1.0 MHz
Description : In communication systems the frequency range used for voice is:
Last Answer : 300 Hz to 3800 Hz
Description : The best frequency demodulator is the:
Last Answer : PLL discriminato
Description : Approximately what is the frequency limit of the optical fiber?
Last Answer : 40 GHz
Description : A waveguide termination having VSWR of 1.1 is used to dissipate 100 watts of power. The reflected power will be A) 0.2268 W B) 0.5868 W C) 0.3468 W D) 0.4568 W
Last Answer : A waveguide termination having VSWR of 1.1 is used to dissipate 100 watts of power. The reflected power will be 0.2268 W
Description : A back-and-forth pattern of motion that transfers energy A. Wave B. Pulse C. Reflection D. Frequency
Last Answer : D. Frequency
Description : For routine cleaning of a commutator, you should apply _____________. A. course sandpaper in a slow back and forth motion across the commutator slots B. an emery cloth parallel to the axis of the machine C. a canvas wiper to the machine while running D. cotton swabs between the commutator bars
Last Answer : Answer: C
Description : It indicates what signal frequencies can be propagated through a given distance of fiber cable. ∙ A. Bandwidth Distance Product ∙ B. Pulse width dispersion ∙ C. Rise time ∙ D. Cutoff frequency
Last Answer : A. Bandwidth Distance Product
Description : If energy is applied at the geometrical center of antenna, the antenna is said to be ___
Last Answer : center-fed
Description : The process of moving from one energy level to another is called __
Last Answer : Absorption
Description : The process of decaying from one energy level to another energy level is called _______
Last Answer : Spontaneous emission
Description : Any energy above the ground state is called ________
Last Answer : excited state
Description : The layer of the atmosphere in which Radio Waves are reflected back is called- (1) Ionosphere (2) Troposphere (3) Stratosphere (4) Exosphere
Last Answer : (1) Ionosphere Explanation: The Radio waves are reflected back to Earth in the Ionosphere which is an electrically charged layer of the upper atmosphere. This process is used to communicate beyond the horizon, atintercontinental distances, mostly in the shortwave frequency bands.
Description : Pick out the wrong statement (A) The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone (B) Mesosphere is characterised by very low atmospheric ... radio waves used in the long distance radio communication are reflected back to earth by stratosphere
Last Answer : (D) The radio waves used in the long distance radio communication are reflected back to earth by stratosphere
Description : Radio waves are reflected back from which layer of the Earth's atmosphere?
Last Answer : Ionosphere
Description : The layer of the atmosphere in which Radio Waves are reflected back is called ; (1) Ionosphere (2) Troposphere (3) Stratosphere(4) Exosphere
Description : A mode where the entire magnetic field is in the transverse plane and has no portion parallel to the length axis.
Last Answer : TM mode
Description : The service are in standard AM broadcast is described as ______ if there is no fading of signal.
Last Answer : Primary
Description : It is logically equivalent to making telephone call through the DDD network except no direct end-to-end connection is made
Last Answer : Virtual call
Description : In a TV receiver the raster is normal but there is no sound and quality of picture is poor. The defective part is
Last Answer : AGC, video IF amplifier, RF amplifier
Description : does its best to get a transmission through to its destination, but with no guarantees
Last Answer : best-effort delivery