Tecnicas digitales 2

1. 1What is the purpose of intermediate production breaks in ARINC 429 or 629 Data cables?.                       
   

   1. ACables are only manufactured 40 feet long.  
   2. BTo allow maintenance personnel to divide the right and left system buses into two parts for easy removal and installation
   3. CTo allow connection of new cables to the existing ones in case of a modification.  
2. 2Where is the parity bit installed in a data word?.                  
   

   1. AFront. 
   2. BEnd MSB.      
   3. CMiddle
3. 3RZ bi-polar modulation consists of bits which are one of __________ states?.                   
   

   1. AEight. 
   2. BTwo.   
   3. CThree. 
4. 4In the ARINC 429 digital information transfer system, data may travel in:.            
   O

   1. Aboth directions on the same bus simultaneously.       
   2. Bone direction only.     
   3. Cboth directions on the same bus sequentially by time multiplexing. 
5. 5An ARINC 629 data word.               
   

   1. Aincludes an 8 bit label and a 16 bit data field.           
   2. Bhas only 20 bits.         
   3. Ccomprises up to 256 data bits.         
6. 6In an ARINC 429 digital word bit number 32 is used for.               
   

   1. Aterminating the data field.     
   2. Bchecking parity.          
   3. C  identifying word type.          
7. 7What connects an LRU to the Bus Coupler in an ARINC 629 Data Bus?.              
   

   1. APatch Cord.    
   2. BStub Cable.    
   3. CInterconnect Cable
8. 8What is the equivalent of this gate?.              
   
   

   1. A= (NOT-A + NOT-B).           
   2. B= (A + B)NOT.          
   3. C= (A.B)NOT. 
9. 9A NOR gate with both inputs inverted becomes a.               
   

   1. ANAND gate.  
   2. BAND gate.     
   3. COR gate.         
10. 10Adding invertors to the two inputs of an AND gate makes a.                      
    

    1. AOR gate.         
    2. BNOR gate.      
    3. CNAND gate.  

11. 11This truth table is for a.                      
    
    

    1. AOR gate.         
    2. BAND gate.     
    3. CNAND gate.  
12. 12Which logic gate can be represented as a parallel circuit?.                
    

    1. AOR gate.         
    2. BExclusive OR gate.    
    3. CNAND gate.  
13. 13Making an inverter from a NAND or NOR gate is achieved by.                  
    

    1. Aconnecting the inputs.
    2. Binverting the input.     
    3. Cconnecting two in series.        
14. 14An AND gate output is 1 when inputs are.               
    

    1. Aboth 1.
    2. Bboth 0.
    3. C1 and 0.          
15. 15What sort of gate requires two positive voltages to operate?.                       
    

    1. AAND. 
    2. BOR.    
    3. CNOT.  
16. 16When will a NAND gate give logic 0 at the output?.                       
    

    1. AWhen both inputs are at 1.     
    2. BWhen the inputs are different.           
    3. CWhen both inputs are at 0.
17. 17Which logic gate has this truth table?.           
    
    

    1. ANOT.  
    2. BNAND.          
    3. CExclusive OR.
18. 18Which logic gate can be represented as a parallel circuit?.                
    

    1. AExclusive OR.
    2. BNAND.          
    3. COR.
19. 19What is this truth table?.                    
    
    

    1. ANOR gate.      
    2. BNOT gate.      
    3. CAND gate.     
20. 20What sort of gate is this?.                  
    
    

    1. ANOT gate.      
    2. BNOR gate.      
    3. COr gate.          
21. 21The output of a NOT gate is logic 1. The input is.                
    

    1. Alogic 0.           
    2. Blogic 1.           
    3. Cboth logic 1.  
22. 22When the voltage that represents a logic 1 state is less than the voltage that represents a logic 0 state, the logic being used is.                       
    

    1. Aeither positive or negative.     
    2. Bpositive.          
    3. Cnegative.         
23. 23The output of an AND gate having two inputs A and B is logic 1. The two inputs will have the logic states of.                     
    

    1. AA = 0, B = 0.  
    2. BA = 1, B = 0.  
    3. CA = 1, B = 1.  
24. 24The output of an OR gate having two inputs A and B is logic 0. The two inputs will have the logic states of.                     
    

    1. AA = 1, B = 0.  
    2. BA = 0, B = 1.  
    3. CA = 0, B = 0.  
25. 25What is this symbol?.             
    
    

    1. AExclusive AND gate. 
    2. BExclusive NOR gate. 
    3. CExclusive OR gate.  
26. 26What Logic Gate does this switch circuit indicate?.             
    
    

    1. ANOR gate.      
    2. BAND gate.     
    3. COR gate.         
27. 27Which logic gate has both inputs high to get an output?.                  
    

    1. AAND gate.     
    2. BOR gate.         
    3. CNAND gate.  
28. 28A NAND and NOR to become a NOT gate have.                
    

    1. Ainputs inverted.          
    2. Boutputs inverted.        
    3. Cinputs connected together
29. 29An AND gate with inverted inputs and an inverted output is equivalent to.                       
    

    1. Aan AND gate. 
    2. Ba NOR gate.   
    3. Can OR gate.    
30. 30Logic gates internal operating mechanisms are produced from.                    
    

    1. Athin film resistors.      
    2. Btransistors.      
    3. Cdiodes.           
31. 31  A logic 1 may be represented in an analogue system by (where Q is an output of a latch / flip-flop).                     
    

    1. Aswitch closed / light off / Not Q.       
    2. Bpositive / magnetised / Q.      
    3. Cswitch open / light on / Q.
32. 32To get logic 1 using this gate.            
    
    

    1. AA and B = 0.  
    2. BA or B = 1.     
    3. CA and B = 1.  
33. 33To get logic 1 using this gate.            
    
    

    1. AA and B = 1.  
    2. BA or B = 1.     
    3. CA and B = 0.  
34. 34What logic gate would this circuit represent?.                       
    
    

    1. ANAND Gate. 
    2. BNOR gate.      
    3. CAND gate.     
35. 35What type of gate is this?.                
    
    

    1. ANAND.          
    2. BNOT.  
    3. CE-OR. 
36. 36What sort of gate requires two negative input voltages to operate?.             
    

    1. AOR.    
    2. BNAND.          
    3. CNOT
37. 37In Positive Logic representation.                   
    

    1. Aboth states have same positive voltages but stage 1 has more current.          
    2. Bstate 1 is more positive than state 0.  
    3. Cstate 0 is more positive than state 1
38. 38Switching within logic gates is normally achieved with the use of.              
    

    1. ABTB's.
    2. Brelays. 
    3. Cdiodes.           
39. 39The truth table of A =0011 B=0101 and =0110 indicates that the logic device is.              
    

    1. Aan ECLUSIVE OR gate.       
    2. Ba NOR gate.   
    3. Can AND gate. 
40. 40What input is required to activate the relay shown?.             
    
    

    1. AA=0 B=1.       
    2. BA=1 B=0.       
    3. CA=1 B=1.       
41. 41A NAND gate has inputs A and B and output C. If the output (c) was zero, what are the inputs?.                 
    

    1. AA=1 B=1.       
    2. BA=0 B=0.       
    3. CA=1 B=0.
42. 42The 'fan-in' in a gate is the.                
    

    1. Anumber of inputs to a gate.    
    2. Bnumber of outputs from a gate.         
    3. Cnumber of inputs and outputs of a gate
43. 43What does the logic circuit shown represent?.                      
    
    

    1. AFull Adder Circuit.    
    2. BHalf adder circuit.      
    3. CMulti-bit adder
44. 44What would be the outputs of this circuit, if A=0 B=0 C=1.                       
    
    

    1. A1, 1.    
    2. B0, 1.    
    3. C0, 0.    
45. 45What would be the outputs of this circuit, if A=1 B=1 C=0.                       
    
    

    1. A0, 1.    
    2. B1, 1.    
    3. C1, 0.    
46. 46Tristate devices are found.                 
    

    1. Aon input circuits.        
    2. Bon output circuits.      
    3. Con both input and output circuits.   
47. 47A full adder has.                    
    

    1. Athree inputs and two outputs.
    2. Btwo inputs and one output.    
    3. Cthree inputs and one output.
48. 48In a computer memory device, which one of these has the slowest access time?.                
    

    1. Afloppy disk.    
    2. Bmagnetic tape.
    3. C8mm video tape.     
49. 49The advantage of DRAM over SRAM is.                 
    

    1. Aare cheaper to manufacture.   
    2. Bhas a larger storage capacity per chip area.    
    3. Cthey operate slower
50. 50A BYTE is usually.                
    

    1. Aan 8 bit word. 
    2. Ba six bit word.
    3. Ca 12 bit word. 
51. 51What is the definition of baud rate?.             
    

    1. A1 word per second.    
    2. B1 byte per second.      
    3. C1 bit per second.         
52. 52Which would have the least components?.                
    

    1. AALU.  
    2. BCPU.  
    3. CLSI.    
53. 53What is a baud?.                    
    

    1. AA bit of data. 
    2. BA block of data.         
    3. CA byte of data.          
54. 54In a bi-stable memory circuit.            
    

    1. Athe memory is retained indefinably.  
    2. Bthe memory is lost as soon as power is removed.      
    3. Cthe memory needs to be refreshed constantly, even when power is on
55. 55What is the advantage of series over parallel message sending?.                  
    

    1. AOnly one pair of conductors. 
    2. BMore information sent.          
    3. CQuicker
56. 56A typical example of a mass storage memory device which is also WORM (Write Once Read Many) is.             
    

    1. Aan IC. 
    2. Ba magnetic tape.         
    3. Ca CD Rom
57. 57A computer using RAM would utilize.                     
    

    1. Amagnetic tape.
    2. Ba compact disc.          
    3. Can integrated circuit (chip).
58. 58Magnetic materials are used in.                      
    

    1. AROMs only.   
    2. Bsome RAMs.  
    3. CEPROM.        
59. 59A typical example of a mass storage device is.                      
    

    1. AIC.      
    2. Bmagnetic tape.
    3. CCD
60. 60What is EPROM?.                 
    

    1. AEnhanced programmable read only memory.
    2. BErasable programmable read only memory.   
    3. CErasable programming read only module
61. 61How many bytes can be carried in a 32bit word?.                
    

    1. A8 bytes.           
    2. B4 bytes.           
    3. C2 bytes.           
62. 62A common used material in computer manufacturing is.                  
    

    1. Aferrite material.           
    2. Bpermeamag material.  
    3. Cferromagnetic material.      
63. 63Ferrite medium is used for computer memory because.                    
    

    1. Adata is stored after the power is removed.     
    2. Bit is light.        
    3. Cit has low eddy current losses.   
64. 64Data is usually stored in.                    
    

    1. ARAM. 
    2. BROM. 
    3. CEEPROM.      
65. 65Registers are used in digital computers to.                
    

    1. Astore bits of information in a permanent memory.     
    2. Bstore a limited amount of information on a temporary basis.
    3. Ckeep a count of operations completed.   
66. 66A computer consist of at least the C.P.U and.                      
    

    1. Amemory and input & output port.      
    2. Bmemory, ALU, input & output port. 
    3. Cregister section, ALU, timing and control section
67. 67A basic computer would consist of.              
    

    1. Aregister section, ALU and timing and control section.          
    2. Bmemory, input/output ports and CPU.          
    3. CRAM/ROM and input/output ports
68. 68DRAM.                      
    

    1. Arequires a refreshing charge.  
    2. Bmemory is stored when power supply is removed.    
    3. Cit does not require a refreshing charge
69. 69Bubble memory stores data on.                     
    

    1. Amagnetic tape.
    2. Bsemiconductor material.         
    3. Cferrite core.     
70. 70An EPROM.              
    

    1. Ais non-volatile memory.          
    2. Brequires constant refreshing.  
    3. Cis erased after reading. 
71. 71A computer requires to operate, a.                 
    

    1. Aaddress bus, a data bus only. 
    2. Bdata bus, a control bus, a address bus.           
    3. Cdata bus, a control bus only.  
72. 72data bus, a control bus only.              
    

    1. ADRAM.          
    2. BSRAM.           
    3. CRAM. 
73. 73A computer is acting in real time when.                    
    

    1. Athe CPU requires a clock pulse.         
    2. Bthe output is equal to the input of data.         
    3. Cthe time to access memory is equal to the data speed in.     
74. 74What is the function of a status register in a microprocessor?.                      
    

    1. ATo indicate the status of the processor.         
    2. BIn the ALU, to store the position of the program during an interrupt.          
    3. CTo synchronize the clock pulse
75. 75What is the purpose of the ALU?.                 
    

    1. ATo store data being used by the CPU.           
    2. BThe part of the CPU unit where arithmetic & logic operations are carried out.        
    3. CTo convert serial into parallel data
76. 76The CPU consists of.             
    

    1. AALU, timing and control section, register.    
    2. Bregister and arithmetic logic unit only.          
    3. Cregister, timing and control section only
77. 77How is multiplication achieved in an ALU?.            
    

    1. Aby addition.    
    2. Bby subtraction.           
    3. Cby coupling
78. 78The smallest operation of a CPU is.               
    

    1. Athe processor cycle.    
    2. Bthe processor sub-cycle.         
    3. Cthe time cycle.
79. 79Where does the clock signal in a microprocessor come from?.                      
    

    1. AALU.  
    2. BMemory.         
    3. CControl unit.   
80. 80Where is the operating program for the CPU stored?.                      
    

    1. AControl unit.   
    2. BALU.  
    3. CMemory unit. 
81. 81A priority encoder.                 
    

    1. Aoutputs the highest input.      
    2. Boutputs the selected input.     
    3. Coutputs the lowest input
82. 82The smallest operation possible in a computer is the.            
    

    1. Atiming cycle.   
    2. Bprocessor sub-cycle.   
    3. Cprocessor cycle
83. 83A clock pulse in processor equipment.                       
    

    1. Ais to synchronise everything.  
    2. Bis used for the maintenance tests.      
    3. Cis to give the correct timing when calculations are made. 
84. 84In a computer, the code that fetches correct data and feeds it to the ALU is called.                       
    

    1. Athe instruction set.      
    2. BARINC.         
    3. Cthe computer program.
85. 85A computer processor has within it.              
    

    1. Aregister, buffer, data bus.       
    2. BALU, register, memory.         
    3. CALU, control section, register.        
86. 86The arithmetic logic unit (ALU) in a central processor unit (CPU) carries out.                    
    

    1. Aaddition, subtraction, multiplication and division.    
    2. Bcomputations as instructed.   
    3. Ctiming and synchronisation
87. 87The CPU requires a clock to determine.                    
    

    1. Athe number of bits on the highway.   
    2. Bthe speed of operation.          
    3. Cthe date and time.
88. 88An ALU performs the following.                  
    

    1. AArithmetic, Logic, Branch and Move Operations.    
    2. BInput/Output operations, Arithmetic, Logic Functions.        
    3. CArithmetic, Logic, Branch and Find Operations
89. 89What function do gates 1 and 2 perform?.                
    
    

    1. AFull adder.      
    2. BHalf Adder.   
    3. C   Shift Register.
90. 90On an IC, pin 1 is to the left of the notch. Which way are the pins numbered?.                  
    

    1. ALeft to right.  
    2. BAnticlockwise.           
    3. CClockwise
91. 91When 4 binary serial counters are connected in cascade for frequency division, what division factor is required?.               
    

    1. A8.        
    2. B16
    3. C4
92. 92    3 binary counters in cascade. What is the division?.             
    

    1. A32
    2. B8
    3. C16
93. 93Within a 3 bit frequency cascade, division is to.                   
    

    1. A2
    2. B4
    3. C8
94. 94Very Large Scale Integrated (VLSI) means the number of gates in a single IC is.              
    

    1. Aup to 10,000.  
    2. Bover 10,000.   
    3. Cup to 1000.     
95. 95An encoder changes.              
    

    1. Adigital to analogue.    
    2. Banalogue to digital.    
    3. Cdata from one format to another.   
96. 96An RS flip-flop with Q at 1 is said to be.                  
    

    1. Aset.      
    2. Breset.   
    3. Czero
97. 97When a JK flip flop is used as a memory device, what type of memory would it be?.                       
    

    1. Aread-only.       
    2. Bnon-volatile.   
    3. Cvolatile
98. 98In an RS flip flop, output is one. This means it is.                 
    

    1. Aintermediate.  
    2. Breset.   
    3. Cset.      
99. 99An ALU is an example of.                 
    

    1. AMSI.   
    2. BSSI.    
    3. CLSI
100. 100With a j-k flip flop which is the output set.               
     

     1. Aq = 1.  
     2. Bq = 0.  
     3. Ceither. 
101. 101Data is converted from serial to parallel and parallel to serial by.                 
     

     1. Aa synchronous counter.          
     2. Ba parallel register.       
     3. Ca shift register.         
102. 102A typical characteristic of a CMOS is.                      
     

     1. Ahigh power dissipation.          
     2. Bhigh voltage handling.           
     3. Clow power dissipation
103. 103The pins on an op amp are numbered.                       
     

     1. Aanticlockwise.
     2. Bclockwise.      
     3. Ccross ways.     
104. 104A parallel register.                  
     

     1. Arequires a clock pulse for each bit.     
     2. Breads each bit to be stored simultaneously.   
     3. Creads the stored data when logic 0 is applied to the read line.
105. 105A device, which converts serial to parallel and parallel to serial for arithmetical functions, is a.            
     

     1. AParallel to serial and serial to parallel converter.        
     2. BShift Register.
     3. CMultiplexer and De-Multiplexer.   
106. 106What is the device used to convert Binary Coded Decimal into separate supplies for a seven segment digital display?.                     
     

     1. AMultiplexer.    
     2. BDecoder.        
     3. CDemultiplexer.           
107. 107Operation of a frequency counter is such that.                      
     

     1. Ait compares the incoming waveform with standard sine waves.       
     2. Bit detects incidences of peak value.   
     3. Cit changes the incoming waveform to a standard square wave. 
108. 108An example of a small size integrated circuit would be.                   
     

     1. ADIP switch.    
     2. BControl Processor Unit.         
     3. CALU.  
109. 109What is this?.             
     
     

     1. ACounter.         
     2. BShift register. 
     3. CMultiplexer.    
110. 110In a Master Slave, negative edge triggered JK flip flop, both inputs are connected to logic 1. The output.                
     

     1. Awill change state when the leading edge of the clock pulse is applied.         
     2. Bwill change state when the trailing edge of the clock pulse is applied.         
     3. Cdoes not change state when a clock pulse is applied.
111. 111A 12 bit 16 Channel encoder will use a multiplexer with.                 
     O

     1. A3 bit parallel address line.      
     2. B4 bit parallel address line.      
     3. C2 wire series address line. 
112. 112How many address lines would be needed for an 8 line MU?.                     
     

     1. A2
     2. B3
     3. C4
113. 113In a MU, how is parallel converted to serial?.                       
     

     1. ABy way of a shift register.     
     2. BBy way of an encoder.           
     3. CBy way of a demultiplexer
114. 114A multiplexer.            
     

     1. Atakes many signals in and converts it to a serial transmission output.           
     2. Btakes many signals in and puts these in a parallel transmission on the output.          
     3. Ctakes one signal in and converts it to a parallel transmission output
115. 115A multiplexer in test equipment could be used for.               
     

     1. Afrequency divider.      
     2. Banalogue to digital converter.
     3. Cdigital to analogue converter.
116. 116An 8 data input multiplexer has how many Data Select lines.                      
     

     1. A8
     2. B3
     3. C2
117. 117The signal sent between a MU/DEMU is controlled by.                   
     

     1. Aclock.  
     2. Bthe ALU.        
     3. Ccontrol unit.    
118. 118Some of the advantages of fibre optic cable over copper cables are.            
     

     1. Anon conductive, easy to manufacture and assemble, more robust, cheap.     
     2. Bsmaller in size and weight, non conductive, higher security and higher bandwidth.
     3. Cnon conductive, smaller in size and weight, easy to manufacture and assemble and higher security.           
119. 119A fibre optic cable consists of.                      
     

     1. Aa silica glass core with a cladding having a lower refractive index.  
     2. Ba silica glass core with a cladding having a higher refractive index. 
     3. Ca plastic core with a cladding having a higher refractive index
120. 120Fibre optic cables.                  
     

     1. Aare immune to EMI.   
     2. Battenuate EMI.           
     3. Care susceptible to EMI.         
121. 121 Two connected fibre optic cable ends are parallel but not quite touching. This is called.                       
     

     1. Aend to end coupling.  
     2. Blens connector.           
     3. Cend fire coupling
122. 122A disadvantage of a fibre optic cable is.                   
     

     1. Acouplings susceptible to ingress of fluid.       
     2. Bend terminals are susceptible to environmental contamination.         
     3. Cshallow bend radius allowed.
123. 123What kind of light is used in a fibre optic systems?.             
     

     1. AInfrared.         
     2. BVisible.           
     3. CUltraviolet.     
124. 124Fibreoptic data is sent by.                  
     

     1. Amodulating the frequency of a laser beam.    
     2. Ba strobe light. 
     3. Cmodulating the frequency of a filament beam
125. 125HIRF is prevented from entering a fibre optic cable by.                   
     

     1. Ausing an opto-isolator coupling.         
     2. Bgrounding the fibre at both ends.      
     3. Cenclosing it in a metal braid.  
126. 126Continuity of a fibreoptic cable is checked by.                     
     

     1. Aa calibrated light source.        
     2. Ba calibrated light source and an opto-power meter.   
     3. Ca light source and an opto-power meter.   
127. 127A fibreoptic data bus used on an aircraft.                 
     

     1. Acan send only one message at a time.
     2. Bcan transmit on several channels at the same time.    
     3. Cconnects non-essential systems only
128. 128Light travels along a fibre optic by.               
     

     1. Arefraction.       
     2. Breflection.       
     3. Cdispersion. 
129. 129What is the main disadvantage of a fibre optic data bus?.                
     

     1. ALess strong and durable when compared to twisted pair and coaxial cable. 
     2. BExpensive to install.   
     3. CBend radius and moisture ingress at connections.  
130. 130A typical fibre optic connector is.                  
     

     1. AF-type connector.       
     2. Bcoupling type, with lens fitted.          
     3. Cpush-pull connector.   
131. 131Which of the following is an optoelectronic device?.                       
     

     1. ATriac.  
     2. BLaser Diode.  
     3. CThyristor.        
132. 132What is the advantage of a single mode fibreoptic over ordinary wire?.                  
     

     1. ANot prone to damage.
     2. BLarge bandwidth.      
     3. CSmall bend radius.     
133. 133A fibreoptic light source is normally.             
     

     1. Aa strobe light. 
     2. Ba filament lamp.         
     3. Ca laser or LED.          
134. 134The fibreoptic cable can be identified on aircraft by its jacket colour which is.                   
     

     1. Apurple.
     2. Byellow.           
     3. Cred.     
135. 135For a fibre optic cable connector that is not regularly disconnected you would use the.                       
     

     1. Abutt type.        
     2. Bball lens type. 
     3. Cceramic lens type.
136. 136  What maintenance problems are associated with fibreoptics?.                      
     

     1. ACorrosion.      
     2. BKinking and contamination of connectors.    
     3. CEarthing faults.  
137. 137A fibreoptic data bus.            
     

     1. Acan transmit several messages simultaneously.          
     2. Bis only used for non essential messages.        
     3. Ccan only transmit 1 message at a time
138. 138A fiberoptic cable to LRU connector should be connected.             
     

     1. Avery carefully to ensure alignment and reduce light loss.      
     2. Busing torque-loaded pliers.     
     3. Chand tight only
139. 139Some of the advantages of fibreoptic cable over copper cable are.               
      
     

     1. Asmaller size and weight, non conductive, more rugged, higher security.      
     2. Bnon conductive, easy to manufacture and assemble, higher bandwidth.      
     3. Cnon conductive, higher bandwidth, higher security, smaller size and weight.         
140. 140In a single mode fibreoptic cable.                  
     

     1. Aseveral waves travel down the cable. 
     2. Bthe diameter of the cable is dependent on the wavelength of the light used.           
     3. Cthe distortion of the signal is dependent on the length of cable
141. 141A semiconductor which emits photons and releases electrons when stimulated by photons is called.                   
     

     1. Aa photodiode. 
     2. Ba laser diode.  
     3. Can LED.         
142. 142What does a fibreoptic star connection do?.             
     

     1. AProvides a continuous loop of fibre interconnecting all nodes.         
     2. BProvides direct point-to-point services to units on dedicated lines emanating from the central hub.           
     3. CShares a common bandwidth of a common cable
143. 143A fibreoptic lens type coupling with lens and integral LED compared to an end-fire coupling is.                 
     

     1. Amore efficient.
     2. Bless efficient.  
     3. Cequally efficient.       
144. 144Passive sensors in fibreoptics.            
     

     1. APassive sensors in fibreoptics.
     2. Brequire power for processing the signal before they send them down the fibre optic.          
     3. Crequire no power and they do not process signals.   
145. 145Optical fibre losses are due to.                       
     

     1. Aabsorption only.         
     2. Babsorption, scattering and reflection. 
     3. Cradiation, absorption and reflection
146. 146The cone of acceptance is measured between.                      
     

     1. Athe two outer angles.  
     2. Bthe two outer angles.  K
     3. Clongitudinal axis of the core and the outer angle
147. 147Fibreoptic cables use.             
     

     1. Arefractive outer shell. 
     2. Breflective inner shell.  
     3. Creflective outer shell
148. 148In fibreoptic cable, signals are separated by.             
     

     1. Aactive optic filter.       
     2. Blow pass filter.
     3. Cpassive optic filter.  
149. 149Most fibreoptic connectors are designed so.             
     

     1. Athe receptacle has to be torqued to a designated value to ensure correct alignment.
     2. Bthe connectors can not be over tightened.     
     3. Cthe connector can not be replaced on the aircraft.
150. 150The light source used in fibreoptics is.                       
     

     1. Avisible light.    
     2. B  lower bandwidth than visible light.   
     3. Chigher bandwidth than visible light.  
151. 151Light transmission in a fibreoptic cable is due to.                 
     

     1. Arepeated internal reflection.   
     2. Bdefraction of the light.           
     3. Crefraction of the light.
152. 152The name given to the joining of two fibreoptic cables by aligning them carefully and bringing them into close proximity of each other is.              
     

     1. AFusion.           
     2. BLens Coupling.           
     3. CEnd to end
153. 153       In a fibreoptic cable.              
     

     1. Amultiple data signals can be sent down it at one time.          
     2. Bdata can only be sent in one direction.          
     3. Conly one data signal can be sent down it at any one time.
154. 154Fibreoptics relies on.              
     

     1. Afibre absorbing light.  
     2. Blight escaping cladding.         
     3. Clight reflecting off cladding.  
155. 155The 'light' emitted from a LED used within a fibre-optic system will have a wavelength.                
     

     1. Aslightly shorter then that of visible light.       
     2. Bequal to that of visible light.  
     3. Cslightly longer then that of visible light.      
156. 156Sensors in a fibreoptic flight control system.             
     

     1. Arequire processing to give output.      
     2. Bdoes not require power.         
     3. Crequire power for processors.
157. 157Fibreoptic systems can transmit data in.                    
     

     1. Ain two directions.       
     2. Bboth directions at the same time.       
     3. Cone direction only.     
158. 158For high bandwidth high-speed fibreoptic transmission what sort of cable would you use?.               
     

     1. AStep index.     
     2. BSingle mode.  
     3. CGraded index.
159. 159In fibreoptics the wavelength of the light is.             
     

     1. Amore than visible light.           
     2. Bequal to that of visible light.  
     3. Cless than visible light
160. 160What is the advantage of an ILD over an LED when used as a light source in fibre optics?.                       
     

     1. ALower frequency range.         
     2. BLower intensity.         
     3. CHigher bandwidth
161. 161Speed of light in a fibreoptic fibre.                
     

     1. Aincreases if it passes through material of higher refractive index.     
     2. Bis always the same no matter what material it is.       
     3. Cis never greater then the speed of light in free space
162. 162The angle of incidence of a beam of light in a fibreoptic cable will be.                    
     

     1. Atwice that of the cone of acceptance.
     2. Bapproximately half that of the cone of acceptance.   
     3. Cparallel with the end of the cable.      
163. 163In an optical fibre, the angle of acceptance is.                       
     

     1. A1/2 the signal wavelength.     
     2. Bequal to the cone of acceptance.        
     3. C1/2 the cone of acceptance.  
164. 164       When using a TDR (time delay reflectometer) the loss value of the cable is.                       
     

     1. Ashown by the curve on the screen.     
     2. Bset on the TDR.          
     3. Callowed for in the calculation.      
165. 165Common aircraft fibreoptics use.                   
     

     1. Amodulating intensity on direct read.  
     2. Bmodulating intensity on indirect read.           
     3. Cmodulating frequency on direct read.
166. 166What is the main cause of attenuation in fibreoptics?.                      
     

     1. APoor termination.       
     2. BRefractive index.       
     3. CBends in the cable.   
167. 167What is the advantage of a laser diode over an LED?.                     
     

     1. AGreater bandwidth.    
     2. BNarrower bandwidth.
     3. CThere are no advantages.     
168. 168A 'type A' fibre optic connector.                   
     

     1. Ais used when regular disconnection and re-connection of a cable is required.          
     2. Bproduces a larger light loss that a type B connector. 
     3. Cwould be used for connections not regularly disconnected. 
169. 169The inside of a CRT consists of.                    
     

     1. Aan oxide coating and rare mercury gas.         
     2. Ba phosphor coating and rare mercury gas.      
     3. Ciodine and rare mercury gas
170. 170CRT horizontal beam control is achieved by a.                     
     

     1. Asinusoidal wave.         
     2. Bsquare wave.  
     3. Csawtooth wave.        
171. 171         In a CRT, if the magnetic field is parallel to the Y plates, what will be the direction of the electron beam movement?.                      
     

     1. AHorizontal.     
     2. BVertical.         
     3. CNo movement.     
172. 172Primary colours of a CRT are.                       
     

     1. Ared, green and yellow.           
     2. Bred, blue and yellow. 
     3. Cred, green and blue
173. 173What are the effects of the X and Y plates on a CRT?.                    
     

     1. AY plates move the beam vertically, X plates move the beam horizontally.   
     2. BX plates move the beam vertically, Y plates move the beam horizontally.   
     3. CX and Y plates can move the beam in either direction.       
174. 174EADI sky and ground display is provided by.                      
     

     1. Asynthetic TV signals.  
     2. Bstroke pulse.   
     3. Craster scan
175. 175What frequency creates the raster effect on a CRT?.            
     

     1. A50/60 Hz.       
     2. B250Hz.           
     3. C400 Hz.          
176. 176The sweep waveform used on a electromagnetic CRT is.                 
     

     1. Atrapezoidal.    
     2. Bsinusoidal.      
     3. Csawtooth.       
177. 177What shape does the waveform take to counter the impedance effect of the coils in an electromagnetic controlled CRT?.                 
     

     1. ASawtooth.       
     2. BRectangular.   
     3. CTrapezoid.      
178. 178Magnetic deflection in a CRT is achieved by.                       
     

     1. Aa sawtooth waveform.           
     2. Ba trapezoidal waveform.        
     3. Ca sinusoidal voltage.   
179. 179The timebase in a CRT consists of.                
     

     1. Aan amplifier and an oscillator.
     2. Ban oscillator only.       
     3. Can amplifier only.    
180. 180What creates the raster effect on a CRT?.                 
     

     1. ASawtooth frequency.  
     2. BTrapezoidal frequency.          
     3. CSinusoidal frequency
181. 181LCD screens are driven by.               
     

     1. AAC voltage.    
     2. Bvariable current DC voltage.  
     3. Cfixed current DC voltage.    
182. 182A Liquid Crystal Display (LCD) has the advantage over a CRT that.                     
     

     1. Ait requires no cooling. 
     2. Bit displays more colours.        
     3. Cit requires less servicing.  
183. 183The release of a photon by another photon is the principle of.                      
     

     1. Aa photo diode.
     2. Ba zener diode. 
     3. Can LED.         
184. 184If a magnetic field is parallel to the X plates in a CRT, which way will the beam move?.            
     

     1. AVertically.      
     2. BHorizontally.  
     3. CDiagonally.     
185. 185An LED display is.                
     

     1. Amonochrome only.     
     2. Bred and green.
     3. Chigh definition.          
186. 186An LCD display uses what type of power supply?.              
     

     1. ADC voltage.    
     2. BContinuous AC.         
     3. CVariable level DC voltage
187. 187 A beam deflection on EFIS displays are.                  
     

     1. Aelectrostatic.   
     2. Belectromagnetic.         
     3. Csolid state.      
188. 188The supply to an LCD is.                   
     

     1. AAC.    
     2. Bcurrent restricted DC.
     3. Cvoltage restricted DC
189. 189An LED will emit light when.                       
     

     1. Ait is reverse biased.     
     2. Beither forward or reverse biased if a sufficient level of  ac voltage is applied.         
     3. Cit is forward biased.   
190. 190  A CRT display has the advantage over an LCD display of a.                      
     

     1. Abrighter clearer output.           
     2. Bmore energy efficient.
     3. Clarge viewing angle
191. 191To display a circle on a CRT you use.                       
     

     1. A2 square wave 90 degrees out of phase.        
     2. B2 sine waves 180 degrees out of phase.         
     3. C2 sine waves 90 degrees out of phase.  
192. 192To deflect the beam of a CRT horizontally, coils are placed on the neck of the tube.                       
     

     1. Aeach side.       
     2. Btop and bottom.         
     3. Cone on the side, one at the bottom.   
193. 193If the magnetic deflection plates produce a magnetic field which is parallel to the horizontal then the trace is deflected in.                    
     

     1. Acircular motion.          
     2. Bhorizontal axis.           
     3. Cvertical axis
194. 194The most common CRT control for an EFIS system screen is.                     
     

     1. Aa combined system.    
     2. Ban electrostatic system.          
     3. Can electromagnetic system
195. 195   L.E.D.s can give.                   
     

     1. Ahigh definition displays.        
     2. Bmonochrome displays only.   
     3. Cred and green displays only
196. 196At low ambient temperatures, an LCD screen.                      
     

     1. Ais slower to update as data changes.  
     2. B  viewing angle becomes larger.           
     3. Closes contrast
197. 197Colour CRT shadow mask screen resolution is.                    
     

     1. A400 lines per square inch.       
     2. B84 triads.        
     3. C600 lines per scan.      
198. 198An LCD display.                   
     

     1. Ahas three colours only.           
     2. Bis monochrome.          
     3. Chas infinite colours. 
199. 199A segmented configuration for the display of alphanumeric data requires.              
     

     1. Athe starburst display for numbers and lower case letters only.          
     2. B16 segments to display the full range of capital letters and numerals.          
     3. Cat least 13 segments for all upper and lower case letters
200. 200Electronic CRT beam display is used typically in.                
     

     1. Aweather radar indicators.       
     2. BIRU control display units.     
     3. Cdistance measuring indicators; digital counters.

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Test sobre Tecnicas digitales 2, creado por oriol arrufat el 24/06/2018.

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oriol arrufat

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