Description : What are the three types of line losses associated with transmission lines?
Last Answer : Copper, dielectric, and radiation.
Description : . A non-resonant line is a line that has no standing waves of current and voltage on it and is considered to be flat. Why is this true?
Last Answer : The load impedance of such a line is equal to Z0.
Description : The presence of standing waves on a transmission line is the result of A. a high level of attenuation on the line. B. terminating the line by a resistive load equal in value to the surge impedance ... input power to below its critical level. D. an impedance mismatch between the load and the line.
Last Answer : D. an impedance mismatch between the load and the line.
Description : What are the two common causes of transmission-line deterioration?
Last Answer : Corrosive effects of salt water and weather extremes.
Description : . What are two of the three physical factors that determine the values of capacitance and inductance of a transmission line?
Last Answer : (1) Type of line used, (2) dielectric in the line, and (3) length of line.
Description : The types of Unguided transmission channel or media used for LAN are __. A. Twisted Pair Cables B. Coaxial Cables C. Radio Waves D. All the above
Last Answer : C. Radio Waves
Description : What characteristic is determined by the time required for a voltage wave to travel from the input end of an artificial transmission line to the output end and back again?
Last Answer : Pulse width
Description : The actions of the tr and atr circuits depend on the impedance characteristics of what length of transmission line?
Last Answer : Quarter-wavelength section
Last Answer : Pulse width.
Description : Is it possible for a transmission line to operate improperly at certain frequencies and properly at others?
Last Answer : Yes, it is quite common.
Description : At what points along a transmission line will a neon lamp glow the brightest?
Last Answer : At standing-wave voltage peaks.
Description : What is the result of an impedance mismatch between a receiver or transmitter and its transmission line or antenna?
Last Answer : High vswr, which equates to poor reception or a loss of power output.
Description : On an open-ended transmission line, the voltage is always zero at what distance from each end of the line?
Last Answer : One-fourth the distance from each end of the line.
Description : All the power sent down a transmission line from a transmitter can be transferred to an antenna under what optimum conditions?
Last Answer : When the characteristic impedance of the transmission line and the load impedance are equal.
Description : Describe the leakage current in a transmission line and in what unit it is expressed.
Last Answer : The small amount of current that flows through the dielectric between two wires of a transmission line and is expressed in micro ohms per unit length.
Description : A transmission line is said to have distributed constants of inductance, capacitance, and resistance along the line. What units of measurement are used to express these constants?
Last Answer : Inductance is expressed in micro henrys per unit length, capacitance is expressed in picofarads per unit length, and resistance is expressed in ohms per unit length.
Description : What must the physical length of a transmission line be if it will be operated at 15,000,000 Hz?
Last Answer : . λ = 20 meters
Description : What type of transmission line is often used to connect a television set to its antenna?
Last Answer : Twin lead.
Description : What term is used for the end of the transmission line that is connected to an antenna?
Last Answer : Output end, receiving end, load end and sink.
Description : What term is used for the end of the transmission line that is connected to a transmitter?
Last Answer : Input end, generator end, transmitter end, sending end, and source.
Description : In swept-frequency testing the impedance of a transmission line, what electrical characteristic is actually being measured?
Last Answer : Swr on the transmission line.
Description : What is the main advantage of using a time-domain reflectometer (tdr) to test a transmission line?
Last Answer : Tdr will indicate the nature of and the distance to or location of any faults.
Description : To measure incident power, you must rotate the coupler detector of the wattmeter so that the arrow indicating power flow points toward which end of the transmission line?
Last Answer : Load.
Description : List the five types of transmission lines in use today.
Last Answer : Parallel two-wire, twisted pair, shielded pair, coaxial line and waveguide.
Description : What are the two main sources of emi with which radio waves must compete?
Last Answer : Natural and man-made interference.
Description : Compared to the velocity of propagation of waves in air, what is the velocity of propagation of waves in waveguides?
Last Answer : Slower.
Description : What type circuit is used to produce square or rectangular waves?
Last Answer : Multivibrator.
Description : What is the term for multiple reflections of sound waves?
Last Answer : Reverberation.
Description : Sound waves transmitted from a source are sometimes weak when they reach the detector. What instrument is needed to boost the weak signal?
Last Answer : An amplifier.
Description : What are some examples of transverse waves?
Last Answer : Radio waves, light waves, and heat waves.
Description : Which radio frequency bands use the tropospheric scattering principle for propagation of radio waves?
Last Answer : Vhf and above
Description : How is the term "temperature inversion" used when referring to radio waves?
Last Answer : It is a condition where layers of warm air are formed above layers of cool air.
Description : How does fog affect radio waves at frequencies above 2 gigahertz?
Last Answer : It can cause attenuation by absorbtion.
Description : How do raindrops affect radio waves?
Last Answer : They can cause attenuation by scattering.
Description : There is a maximum frequency at which vertically transmitted radio waves can be refracted back to Earth. What is this maximum frequency called?
Last Answer : Critical frequency.
Description : Which layer of the atmosphere has relatively little effect on radio waves?
Last Answer : Stratosphere.
Description : What is one of the major reasons for the fading of radio waves which have been reflected from a surface?
Last Answer : Shifting in the phase relationships of the wave.
Description : which waveforms on the left have a resultant wave of zero, and what is indicated by these waves?
Last Answer : 2 and 6 have zero resultant wave and they indicate that the incident and reflected waves are 180 degrees out of phase at all parts.
Description : Microwaves can be focused and reflected in the same way as what other type of waves?
Last Answer : Light waves.
Description : The mode theory uses electromagnetic wave behavior to describe the propagation of the light along the fiber. What is a set of guided electromagnetic waves called?
Last Answer : Modes of the fiber.
Description : Light waves obey what law?
Last Answer : The law of reflection.
Description : A substance that is unable to transmit any light waves is known as what type of substance?
Last Answer : Opaque.
Description : A substance that transmits almost all of the light waves falling upon it is known as what type of substance?
Last Answer : Transparent.
Description : When light waves encounter any substance, what four things can happen?
Last Answer : Light waves are either transmitted, refracted, reflected, or absorbed.
Description : If a wave's electric lines of force rotate through 360 degrees with every cycle of rf energy, what is the polarization of this wave?
Last Answer : Circular polarization.
Description : The carrier waves used for the radio transmission have frequency upto A. 15 KHz B. 30 KHz C. 90 KHz D. 150 KHz
Last Answer : ANSWER: B
Description : T.V. transmission cannot cover a very large area because _____ A. The strength of T.V. waves is very limited B. Picture cannot be transmitted clearly after a specific distance C. The shape of the earth is spherical D. The air is not a good conductor of light and sound/waves
Last Answer : ANSWER: C
Description : Which atmospheric Layer is used for the transmission of radio waves?
Last Answer : Ionosphere
Description : T.V. transmission cannot cover a very large area because A. the strength of T.V. waves is very limited B. picture cannot be transmitted clearly after a specific distance C. the shape of the earth is spherical (Answer) D. the air is not a good conductor of light and sound/waves
Last Answer : C. the shape of the earth is spherical (Answer)
Description : Standing waves occurs due to a) Impedance match b) Impedance mismatch c) Reflection d) Transmission
Last Answer : b) Impedance mismatch