Description : During which of the transmit or receive cycles are both the tr and atr tubes of a parallelconnected duplexer ionized (arcing)?
Last Answer : Transmit.
Description : The purpose of amortisseur windings in a synchronous motor is to ______________. A. reduce eddy current losses B. produce a higher power factor C. provide a means for starting D. eliminate arcing between the stator and the rotor
Last Answer : Answer: C
Description : A shading coil used in an AC magnetic controller, functions to _____________. A. reduce vibration and noise in the contactor B. prevent flux buildup in the operating coil C. eliminate arcing when the contacts close D. energize the operating coil and 'pull in' the contacts
Last Answer : Answer: A
Description : Amortisseur windings are installed in a synchronous motor to _____________. A. reduce eddy current losses B. produce a higher power factor C. provide a means for starting D. eliminate arcing between the stator and the rotor
Description : Best reason for pressurizing waveguides with dry air A. To maintain propagation B. To maintain temperature of the waveguide C. To reduce the possibility of internal arcing D. To increase the speed of propagation
Last Answer : C. To reduce the possibility of internal arcing
Description : What is the typical frequency range about the center frequency of a tunable magnetron?
Last Answer : . ±5 percent.
Description : What is the effect on magnetron operation if the magnetic field strength is too high?
Last Answer : The magnetron will not oscillate.
Description : What is the frequency range of magnetron oscillators?
Last Answer : 600-30,000 megahertz.
Last Answer : ±5 percent.
Last Answer : . 600-30,000 megahertz.
Description : Capacitive tuning by inserting a ring into the cavity slot of a magnetron is accomplished by what type of tuning mechanism?
Last Answer : . A cookie-cutter tuner
Description : Magnetron tuning by altering the surface-to-volume ratio of the hole portion of a hole-and-slot cavity is what type of tuning?
Last Answer : Inductive.
Description : Why is the pi mode the most commonly used magnetron mode of operation
Last Answer : Greater power output.
Description : What are the electrons called that give up energy to the ac field in a magnetron?
Last Answer : Working electrons.
Description : Why is the negative-resistance magnetron often operated with reduced filament voltage?
Last Answer : To reduce the effects of filament bombardment.
Description : What starts the oscillations in a negative-resistance magnetron?
Last Answer : The application of the proper magnetic field.
Description : What is the primary difference in construction between the basic magnetron and the negativeresistance magnetron?
Last Answer : The negative-resistance magnetron has a split plate
Description : A magnetron will produce oscillations when the electrons follow what type of path?
Last Answer : Circular.
Description : What element in the magnetron causes the curved path of electron flow?
Last Answer : The permanent magnet.
Description : What controls the output frequency of a magnetron?
Last Answer : . The resonant cavities.
Description : A cylindrical copper block with resonant cavities around the circumference is used as what component of a magnetron?
Last Answer : Anode or plate
Description : What serves as a grid in a magnetron?
Last Answer : A magnetic field.
Description : Hysteresis in a direct current generator is indicated by _____________. A. arcing at the brushes B. pulsating terminal current C. heating of the armature core D. hunting and over control
Description : In the illustration, the purpose of part B is to _________. EL-0033 A. increase resistance in series with the contacts as they close to prevent arcing B. create a magnetic field in the steel ... event of an overload D. provide ventilation to the contact when the breaker is close to rated capacity
Last Answer : Answer: B
Description : Undervoltage trips are frequently installed on switchboard circuit breakers to trip ____________. A. out generators in the event of severe arcing or sparking B. out generators when there is reversal of power ... , but continues to run D. out generators when there is low voltage in the main circuit
Last Answer : Answer: D
Description : The purpose of squirrel-cage windings in a synchronous motor is to ______________. A. provide more precise balancing B. produce a higher power factor C. eliminate arcing between the stator and the frame D. provide a means for starting
Description : What are arcing grounds?
Last Answer : The presence of inductive and capacitive currents in the isolated neutral system leads to formation of arcs called as arcing grounds.
Description : What is Arcing Grounds?
Last Answer : When earth faults occurs, arc with the ground and phase will occur. The arc extinguishes and restrikes as a repeated and regular manner. This is called Arcing Ground.
Description : The arcing contacts in a circuit breaker are made of (a) copper tungsten alloy (b) porcelain (c) electrolytic copper (d) aluminium alloy
Last Answer : (a) copper tungsten alloy
Description : The degree of protection by ground wire depends upon the a. Arcing angle b. Shielding angle c. Power factor d. All of above
Last Answer : The degree of protection by ground wire depends upon the a. Arcing angle b. Shielding angle c. Power factor d. All of above
Last Answer : The arcing contacts in a circuit breaker are made of copper tungsten alloy.
Description : How do you prevent excessive heat buildup on an area of a board when soldering multilead components?
Last Answer : Use a skipping pattern
Description : How does relative humidity over 95% cause excessive tape and head wear?
Last Answer : High humidity causes increased friction as the tape passes over the heads.
Description : What is an excessive heat condition?
Last Answer : A condition in which the heat in or around the circuit increases to a higher than normal level
Description : What is an excessive current condition?
Last Answer : A condition that is not a direct short but in which circuit current increases beyond the designed current carrying ability of the circuit.
Description : The development of excessive test voltages is avoided by the use of meggers equipped with what device?
Last Answer : Friction clutches.
Last Answer : Friction clutches
Description : Which of the following types of HPA is not used in earth stations? A. TWT B. Transistor C. Klystron D. Magnetron
Last Answer : D. Magnetron
Description : What do you call a circuit that controls the magnetron output? A. Inverter B. Impeller C. Modulator D. Converter
Last Answer : C. Modulator
Description : Low-power radar uses A. RIMPATT B. TRAPATT C. Magnetron D. IMPATT
Last Answer : D. IMPATT
Description : Draw the construction of magnetron and describe it’s working.
Last Answer : Working/Operation: 1. Now assume RF oscillations are initiated due to some noise transient within the magnetron, the oscillations will be sustained by device operation. 2. Self- ... these favored electrons imparts enough energy to the RF oscillations so that they are sustained.
Description : With neat cross sectional constructional details,write effect of magnetic and electric field in magnetron
Last Answer : 1)When magnetic & electric fields act simultaneously upon the electron,its path can have any of a number of shapes dictated by the resistive strengths of the mutually perpendicular electric & ... happens because in practice the applied magnetic field is greatly in excess of the cutoff field.
Description : When charging lead-acid batteries, you should reduce the charging rate as the battery nears its full charge capacity to ______________. A. prevent excessive gassing and overheating B. allow equalization of cell voltages C. reduce lead sulfate deposits D. increase lead peroxide formation
Description : Purpose of relief valve in a reciprocating pump is to (A) Protect the pump against developing excessive pressure (B) Facilitate unidirectional flow of liquid (C) Reduce the discharge pressure (D) Control the rate of discharge
Last Answer : (A) Protect the pump against developing excessive pressure
Description : Consider the following statements: Air vessels are fitted on the suction and delivery sides of a reciprocating pump to 1. Achieve higher speed without separation. 2. Reduce work in overcoming frictional resistance. 3. Avoid excessive vibration ... 2 & 3 only (c) 2, 3 & 4 only (d) 1, 2, 3 & 4
Last Answer : (d) 1, 2, 3 & 4
Description : pecific energy requirement of rotary tillers can be reduce by a) Increasing the bite length b) Decreasing depth to diameter ratio c) Both (a) and (b) d) Excessive reduction in total power requirement
Last Answer : c) Both (a) and (b)
Description : What are two disadvantages of procedure oriented languages?
Last Answer : They require more space in memory and they process data at a slower rate than symbolic languages.
Description : What led to the development of procedure oriented languages?
Last Answer : The development of mnemonic techniques and macroinstructions.
Description : What procedure should you use when a power input to your equipment is missing?
Last Answer : Work backwards from the load to the source.