Description : When soldering a printed circuit board component, you should be careful to prevent damage by _________. A. quickly heating the joints, using a high wattage iron B. using the soldering iron tip sparingly C. using only acid cord solder D. applying mechanical pressure to the joints being soldered
Last Answer : Answer: B
Description : Multilayer printed circuit board repair is the responsibility of what 2M repair technician?
Last Answer : Microminiature repair technician.
Description : How is board damage caused by technicians?
Last Answer : Repairs by untrained personnel and technicians using improper tools.
Description : What is one of the major disadvantages of multilayer printed circuit boards?
Last Answer : Difficulty of repair of internal connections.
Description : Name the three methods of interconnecting components in multilayer printed circuit boards.
Last Answer : Clearance hole, plated-through hole, and layer build-up
Description : What is the major disadvantage of printed circuit boards?
Last Answer : Components soldered in place.
Description : List the major advantages of printed circuit boards.
Last Answer : Eliminate heavy chassis and point-to-point wiring
Last Answer : The main printed circuit board of a computer is called mother board.
Description : To avoid damaging the components of a printed circuit board when testing it with a DC volt-ohmmeter, you should _______. A. ground the board B. avoid reversing the polarity of the leads C. isolate sensitive components with heat sinks D. all of the above
Description : Why is it a poor practice to use a high wattage soldering iron when soldering or desoldering components on a printed circuit board? A. The circuit board will blister and warp. B. The foil wire bonded ... board has a low melting temperature. D. The solder is kept to a dull heat dissipating finish.
Description : In electronic circuits, DC voltages can be positive (+) or negative (-) when measured with respect to the _________. A. printed circuit board 'common' trace B. chassis, console frame or hull 'ground' C. analogue or digital circuitry 'common' bus D. all of the above
Last Answer : Answer: D
Description : In electronic circuitry, the abbreviation 'PCB' commonly means ______________. A. pulse coded binary B. printed circuit board C. poly-coated braid D. personal computer bits
Description : Tightly knit metal braid wire can be used with a printed circuit board when ___________. A. conductor flexibility is required B. desoldering components in the circuit C. electrically produced magnetic ... cause inaccuracies in adjacent components D. reactance in the circuit must be kept to a minimum
Description : PCB stands for: a) Process Control Block b) Printed Circuit Board c) Both of The Above d) None of The Above
Last Answer : c) Both of The Above
Description : Your activity stores its magnetic tape in an area where the temperature is 100º F. What two types of environmental damage could occur that would make these tapes unusable?
Last Answer : Head-to-tape sticking and layer-to-layer adhesion
Description : What six types of environmental damage can occur to tapes in storage when the ideal temperature and humidity ranges are exceeded?
Last Answer : Tape deformation, oxide shedding, head-to-tape sticking, layer to-layer sticking, dirt build-up, and excessive tape and head wear.
Description : Environmental damage to magnetic tape can occur when the tape is stored in an area that exceeds what ideal temperature and humidity ranges?
Last Answer : Ideally, use and store tape at 60 to 80º F and at 40 to 60% relative humidity.
Description : If magnetic tape is stored in areas with temperature and humidity extremes, what are three types of tape damage that may occur?
Last Answer : Oxide shedding, layer-to-layer sticking, and tape deformation.
Description : What type of service is NOT provided by the circuit shown in the illustration? EL-0094 A. Logging of engine order signals from the bridge. B. Printed record of alarms as they ... . Visual metering of temperature and pressure conditions. D. Periodic recording of pressure and temperature conditions.
Last Answer : Answer: A
Description : What term is used to identify the procedure of connecting one side of a circuit board with the other?
Last Answer : Interfacial connections.
Description : Which of the following problems will occur if the circuit breaker of the incoming alternator is closed and it is 180° out of phase with the loaded alternator when paralleling? A. The rotor of the ... The rotor of the incoming alternator will stop. D. Both alternators will parallel 180° out of phase.
Description : List two causes of damage to ESD-sensitive electronic components
Last Answer : Esd, improper stowage, and improper handling.
Description : What material is applied to electronic assemblies to prevent damage from corrosion, moisture, and stress?
Last Answer : Conformal coating
Description : How do the tape guides on a tape reeling system protect the tape from damage during operation?
Last Answer : They keep the tape straight with respect to both the supply and take-up reels and the magnetic heads.
Description : You notice steps in the tape pack such as those in figure 2-3. What causes this and how does it damage the magnetic tape?
Last Answer : Pack slip. It's caused by loosely wound tape on a reel that is exposed to excessive vibration or heat. The vibration or heat causes the tape to shift, causing steps in the tape pack. The uneven tape will then rub against the reel's sides and the recorder's tape guides.
Description : When the relative humidity is below 10%, what happens to magnetic tape and parts of a tape recorder that could cause environmental damage?
Last Answer : Dirt build-up caused by static electricity.
Description : List four rules you should follow when storing magnetic tape to protect it from damage.
Last Answer : a. Make sure the tape is wound properly on the reel hub, b. store tapes vertically, c. keep storage area at right temperature and humidity, d. store away from equipment that generates stray magnetic fields.
Description : What structurally large, low-resistance conductor is connected in parallel with the meter movement to prevent damage?
Last Answer : Shunt.
Description : A DISTRESS message differs from an URGENCY message because: a. There is grave and imminent danger which requires immediate assistance b. The aeroplane has suffered damage that endangers the ability ... suitable aerodrome d. The situation concerns the safety of passengers on board or within sight
Last Answer : a. There is grave and imminent danger which requires immediate assistance
Description : A DISTRESS message differs from an URGENCY message because: a. There is grave and imminent danger which requires immediate assistance b. The aeroplane has suffered damage that endangers the ... suitable aerodrome d. The situation concerns the safety of passengers on board or within sight
Description : When troubleshooting a console circuit card suspected of being faulty, first check operating voltages, clean the card and then _________________. A. make sure wired connections and push-on connectors ... circuit traces with an ohmmeter D. measure the gain of each transistor or integrated circuit
Description : When troubleshooting a console circuit card suspected of being faulty, first check for proper voltages to the card and then _______________. A. test transistors or integrated circuits for gain and ... D. de-energize the card and check the printed circuit traces for continuity with an ohmmeter
Last Answer : Answer: C
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 : When a lead is soldered to a pad without passing through the board, it is known as what type of termination?
Last Answer : On-the-board termination.
Description : Modules or submodules attached to a mother board are what packaging level?
Last Answer : Level I.
Description : List five precautions to take when installing fiber optic systems on board naval ships.
Last Answer : a. Never bend an optical fiber or cable at a radius of curvature less than the minimum bend radius. b. Never pull fiber optic cables tight or fasten them over or through sharp corners or ... the hardware. e. Allow only trained, authorized personnel to install or repair fiber optic systems.
Description : Who must initially determine what level of damage would occur to information if unauthorized disclosure of the information occurred?
Last Answer : The Original Classification Authority
Description : An important feature of maple syrup urine disease is (A) Patient can not be treated by dietary regulation (B) Without treatment death, of patient may occur by the end of second year of life (C) Blood levels of leucine, isoleucine and serine are increased (D) Excessive brain damage
Last Answer : Answer : D
Description : Cell membrane damage can occur by C A. free radicals B. Phopholipase C. all of above D. None of these
Last Answer : all of above
Description : The following irregularities occur, they must invariably be noted in the Record officer's daily report (a) Non-attendance or late attendance of a Sorting Assistant on the attendance day at the Record (b) Negligence ... (d) loss of, or damage to any article supplied to the set; (e) All the above
Last Answer : (e) All the above
Description : The most serious complications which may occur from abscess of max canine is: A. Cellulitis B. Cavernous sinus thrombosis C. Lacrimal duct stenosis D. Damage to infra orbital nerves
Last Answer : B. Cavernous sinus thrombosis
Description : What condition must occur to have a change in the output of a D FF?
Last Answer : A positive-going clock pulse.
Description : In what layer of the atmosphere does virtually all weather phenomena occur?
Last Answer : Troposphere.
Description : Where does the greatest amount of ionospheric absorption occur in the ionosphere?
Last Answer : Where ionization density is greatest.
Description : . What causes ionization to occur in the ionosphere?
Last Answer : High energy ultraviolet light waves from the sun.
Description : At what point on an open-circuited rf line do voltage peaks occur?
Last Answer : At 1/2 wavelength from the end and at every 1/2 wavelength along the line
Description : List the three basic errors that occur during fiber alignment.
Last Answer : Fiber separation (longitudinal misalignment), lateral misalignment, and angular misalignment.
Description : Light propagates in multimode graded-index fibers according to refraction and total internal reflection. When does total internal reflection occur?
Last Answer : When the angle of incidence becomes larger than the critical angle of incidence.
Description : What relationship must exist between the electron beam and the traveling wave for bunching to occur in the electron beam of a twt?
Last Answer : The traveling wave must have a forward velocity equal to or less than the speed of the electrons in the beam.
Description : Delay differences between the source wavelengths occur as the optical signal propagates along the fiber. What is this called?
Last Answer : Differential group delay t(l).