Description : The frequency range of a waveguide is determined by what dimensions?
Last Answer : . The "a" dimension.
Description : Choose which of following condition is not required for a waveguide to exist. a) The dimensions should be in accordance with desired frequency b) Cut-off frequency should be minimum 6GHz c) The shape should be spherical d) No specific condition is required for waveguide design
Last Answer : c) The shape should be spherical
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 determines the frequency, bandwidth, and power handling capability of a waveguide probe?
Last Answer : Size and shape
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 : If the inductor and capacitor values are increased, what happens to the resonant frequency?
Last Answer : Decreases.
Description : If all the dimensions of a bar are increased in the proportion n : 1, the proportion with which the maximum stress produced in the prismatic bar by its own weight, will increase in the ratio (A) 1 : n (B) n : 1 (C) 1 : (1/n) (D) 1 : n
Last Answer : (B) n : 1
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 : What is the result of an abrupt change in the size, shape, or dielectric of a waveguide?
Last Answer : Reflections.
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 : What device is used to produce a gradual change in impedance at the end of a waveguide?
Last Answer : Horn.
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 : 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 : 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 field configuration is easiest to produce in a given waveguide?
Last Answer : . Dominant mode
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 : What interaction causes energy to travel down a waveguide?
Last Answer : The interaction of the electric and magnetic fields.
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 : Why is it necessary that incoming alternator frequency is more than bus bar?
Last Answer : Prior to paralleling alternators together, the frequency of the incoming alternator is made slightly higher. This is to ensure that the incoming generator will take some of the bus load. If the incoming ... onto the bus. If this happens it is possible to cause other generators to trip off line.
Description : By which of the following a bus-bar is rated ? (a) Current only (b) Current and voltage (c) Current, voltage and frequency (d) Current, voltage, frequency and short time current
Last Answer : (d) Current, voltage, frequency and short time current
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 : At what frequency compared to the cutoff frequency of a waveguide will the wavefronts be reflected back and forth across the guide (setting up standing waves) and no energy
Last Answer : UHF receiving antenna
Description : Define the term w.r.t. waveguide: (i) Cut-OFF frequency (ii) Group Velocity
Last Answer : Group velocity: It is defined as the rate at which the wave propagates through the waveguide and is given by The group velocity is also can be defined as the velocity of energy flow ... rectangular waveguide at a frequency below fc TE1,0. This is absolute cut off frequency of the waveguide.
Description : A rectangular waveguide is 5.1 cm by 2.4 cm (inside dimension). The cut off frequency of the dominant mode is
Last Answer : A rectangular waveguide is 5.1 cm by 2.4 cm (inside dimension). The cut off frequency of the dominant mode is 2.94 GHz
Description : A rectangular waveguide is 4.2 cm by 1.85 cm. The cut-off frequency of the dominant mode through this waveguide is (a) 3.57 GHz (b) 3.75 GHz (c) 3.70 MHz (d) 3.57 MHz
Last Answer : A rectangular waveguide is 4.2 cm by 1.85 cm. The cut-off frequency of the dominant mode through this waveguide is 3.57 GHz
Description : When the reverse bias on a varactor is increased, what happens to the effective capacitance?
Last Answer : Capacitance decreases.
Description : How can the frequency range of a collinear array be increased?
Last Answer : By increasing the lengths of the elements of the array.
Description : What happens to inductive reactance as frequency increases?
Last Answer : It increases.
Description : What happens to capacitive reactance as frequency increases?
Last Answer : It decreases.
Description : What happens when a frequency meter is adjusted to the frequency of the signal being measured?
Last Answer : Power is absorbed by the frequency meter cavity; and a pronounced dip in power, at the output, will be observed.
Description : What happens to the impedance of interelectrode capacitance as frequency increases?
Last Answer : Impedance decreases.
Description : What happens to an fm signal as you increase the frequency of the modulating signal?
Last Answer : Both the bandwidth and the number of significant sidebands increase.
Description : What happens to the value of XL as frequency increases?
Last Answer : XL increases.
Description : What are the dimensions of a Hershey bar?
Last Answer : 16X7 CM.
Description : A rectangular box has dimensions x, y and z units, where x < y < z. If one dimension is only increased by one unit, -Maths 9th
Last Answer : answer:
Description : Voltage failure of an AC generator may be caused by ____________. A. failure of the exciter generator B. a tripped bus circuit breaker C. high mica segments on the stator bus bar D. excessive prime mover speed
Last Answer : Answer: A
Description : A bus bar is 3 inches wide and 0.375 inches thick. What size of round conductor (in circular mils) is necessary to carry the same current as the bus bar? A. 1,125,000 circular mils B. 1,250,000 circular mils C. 1,432,000 circular mils D. 1,547,000 circular mils
Last Answer : Answer: C
Description : Periodic testing by a shoreside support technician using a special camera which can detect potentially dangerous loose or corroded bus bar and controller connections is termed ______________. A. heat sensitive thermography B. visual pyrotronics C. corrosion electrolysis D. electric vibroanalysis
Description : A bus disconnect link is used to isolate _____________. A. one bus bar from another B. the generator circuit breaker from the bus C. different phases from the equalizer connection D. positive and negative buses from the neutral
Last Answer : Answer: B
Description : What are different Bus bar materials used in Substation?
Last Answer : Busbars are generally made of copper and Aluminum. Aluminim has the advantage of one third the weight of the copper and also Aluminum requires less maintenance and proper use of alloys provide necessary rigidity required for bus material. Aluminum is used widely in EHV and HV stations
Description : When an alternator connected to the bus-bar is shut down the bus-bar voltage will (a) fall (b) rise (c) remain unchanged (d) none of the above
Last Answer : (c) remain unchanged