Description : What is the result of an impedance mismatch in a waveguide?
Last Answer : Standing waves that cause power losses, a reduction in power handling capability, and an increase in frequency and sensitivity.
Description : What field configuration is easiest to produce in a given waveguide?
Last Answer : . Dominant mode
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 is the result of an abrupt change in the size, shape, or dielectric of a waveguide?
Last Answer : Reflections.
Description : Transition curves are introduced at either end of a circular curve, to obtain (A) Gradually decrease of curvature from zero at the tangent point to the specified quantity at the junction of the ... specified amount at the junction of the transition curve with main curve (D) None of these
Last Answer : (B) Gradual increase of super-elevation from zero at the tangent point to the specified amount at the junction of the transition curve with main curve
Description : After chronic systemic therapy, withdrawal of corticosteroids should be gradual because: A. Corticosteroids produce psychological dependence B. Abrupt withdrawal may reactivate the underlying disease C. Abrupt withdrawal produces rebound hypertension D. All of the above are correct
Last Answer : B. Abrupt withdrawal may reactivate the underlying disea
Description : What is the most likely cause of losses in waveguide systems?
Last Answer : Improperly connected joints or damaged inner surface.
Description : What is the most common type of waveguide joint?
Last Answer : Choke joint.
Description : A waveguide bend must have what minimum radius?
Last Answer : Greater than 2 wavelengths.
Description : When a waveguide is terminated in a resistive load, the load must be matched to what property of the waveguide?
Last Answer : . Characteristic impedance.
Description : Loose or inefficient coupling of energy into or out of a waveguide can be accomplished by the use of what method?
Last Answer : Slots and apertures.
Description : What determines the frequency, bandwidth, and power handling capability of a waveguide probe?
Last Answer : Size and shape
Description : Which subscript, in circular waveguide classification, indicates the number of full-wave patterns around the circumference?
Last Answer : First.
Description : The electric field is perpendicular to the "a" dimension of a waveguide in what mode?
Last Answer : TE.
Description : How is the cutoff wavelength of a circular waveguide figured?
Last Answer : 1.71 times the diameter.
Description : What term is used to identify the forward progress velocity of wavefronts in a waveguide?
Last Answer : Group velocity.
Description : incidence and reflection that are perpendicular to the waveguide walls?
Last Answer : Cutoff frequency.
Description : Assuming the wall of a waveguide is perfectly flat, what is the angular relationship between the angle of incidence and the angle of reflection
Last Answer : The angles are equal.
Description : When a wavefront is radiated into a waveguide, what happens to the portions of the wavefront that do not satisfy the boundary conditions?
Last Answer : Decrease to zero.
Description : What interaction causes energy to travel down a waveguide?
Last Answer : The interaction of the electric and magnetic fields.
Description : When the frequency is decreased so that two quarter wavelengths are longer than the "a" (wide) dimension of the waveguide, what will happen?
Last Answer : Energy will no longer pass through the waveguide.
Description : What happens to the bus bar dimensions of the waveguide when the frequency is increased?
Last Answer : The bus bar becomes wider.
Description : The frequency range of a waveguide is determined by what dimensions?
Last Answer : . The "a" dimension.
Description : The large surface area of a waveguide greatly reduces what type of loss that is common in two-wire and coaxial lines?
Last Answer : Copper loss.
Description : The folded waveguide in a bwo serves the same purpose as what component in a twt?
Last Answer : Helix.
Description : How does a waveguide-type lens focus spherical wavefront microwave energy?
Last Answer : Some wavefronts are accelerated so that all wavefronts exit the lens at the same time
Description : Which dispersion mechanism (material or waveguide) is a function of the size of the fiber's core relative to the wavelength of operation?
Last Answer : Waveguide dispersion.
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?
Description : What device in a waveguide system used for stopping or diverting electromagnetic wave as desired? A. Mechanical switch B. Electric switch C. Push-button switch D. Waveguide switch
Last Answer : D. Waveguide switch
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 : What is indicated by gradual blackening at the ends of component 'C' shown in the illustration? EL-0081 A. The unit is in danger of exploding. B. The tube is nearing the end of its useful life. C. The circuit voltage is too high. D. The circuit current is too high.
Last Answer : Answer: B
Description : During ecological succession (a) the numbers and types of animals remain constant (b) the changes lead to a community that is in near equilibrium with the environment and is called pioneer community ( ... area (d) the establishment of a new biotic community is very fast in its primary phase.
Last Answer : (c) the gradual and predictable change in species composition occurs in a given area
Description : According to the idea of punctuated equilibrium, macroevolution usually involves A) slow and gradual change. B) alternating periods of stasis (no change) and rapid change. C) most species becoming extinct in a relatively short time. D) species selection.
Last Answer : B) alternating periods of stasis (no change) and rapid change.
Description : According to the idea of gradualism, macroevolution usually involves A) slow and gradual change. B) most species becoming extinct in a relatively short time. C) alternating periods of stasis (no change) and rapid change. D) species selection.
Last Answer : A) slow and gradual change.
Description : What components form the input-signal-developing impedance for the amplifier?
Last Answer : C2 and the secondary of T1.
Description : If the output impedance of an amplifier circuit is decreased, what is the effect on the gain?
Last Answer : The gain decreases.
Description : If the input-signal-developing impedance of an amplifier is increased, what is the effect on the gain?
Last Answer : The gain increases.
Description : In a parallel-resonant circuit, what is the relationship between impedance and current?
Last Answer : Maximum impedance, minimum current.
Description : In a series-RLC circuit, what is the condition of the circuit if there is high impedance, low current, and low reactance voltages
Last Answer : Nonresonant (circuit is either above or below resonance)
Description : . In an "ideal" resonant circuit, what is the relationship between impedance and current?
Last Answer : Impedance low Current high.
Description : When compared to the JFET, what is the input impedance of the MOSFET?
Last Answer : The MOSFET has a higher input impedance.
Description : If the impedance of the choke is increased, will the ripple amplitude increase or decrease?
Last Answer : Decrease.
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
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 : What do impedance-angle meters and vector bridges have in common?
Last Answer : Both measure phase angle and magnitude in determining impedance.
Description : What is the range of the characteristic impedance of lines used in actual practice?
Last Answer : Between 50 and 600 ohms.
Description : What symbol is used to designate the characteristic impedance of a line, and what two variables does it compare?
Last Answer : Z0 and it is the ratio of E to I at every point along the line.
Description : What is the impedance of a crystal at its resonant frequency when it is used in the series mode?
Last Answer : Minimum.
Description : What is the impedance of a crystal at its resonant frequency when it is used in the parallel mode?
Last Answer : Maximum