1 With regard to Kirchhoff's Laws which of the following statements is true?

A There are two laws: the law of us and the law of the meshes
B There are three laws: the law of us, the law of the networks and the law of the meshes
C There are two laws: the law of the networks and the law of the sources
D None of the statements is correct

2 The law of Kirchhoff mesh, also referred to as

The law of power law B tensions C chains of law
D law of resistance

In a parallel circuit 3 as the total current is related to the individual current on each of the branches of said circuit?
A The total current is equal to the average value of the currents in the various branches
B Total current decreases as parallel branches are being added to the circuit
C. The total current is the sum of the currents in the various branches
D total current is the sum of the inverse of each individual voltage drop

A Faraday cage 4

It constitutes an effective protection with regard to electromagnetic fields
B is an effective protection in respect of sound waves
C is an effective protection with regard to earthquakes
D None of the above is correct

5 Generally, which of the following transmission lines has the best shield to electromagnetic fields?
Coaxial Cable
B PLC - "Power Line Communications"
C Telephone Par
D All have armor



6 Which of the expressions define the effectiveness of the shield (S) to electric fields (with "Hey" the intensity of the electric field incident and "Et" the intensity of the electric field transmitted through the screen)?
S = 20 + log (Ei / Et) S B = 1-log (Ei / Et) C = S 20xlog (Ei / Et) D-O = 20 log (Ei / Et)

7 Which of the following statements is correct?

The The ionosphere is a shield around the Earth, the electromagnetic fields for optical radiation only
B The ionosphere is a shield around the Earth, the electromagnetic fields just above 1 GHz
C The ionosphere is a shield around the Earth, the electromagnetic fields in all frequency
D The ionosphere is a shield around the Earth, the electromagnetic fields in certain frequency

8 What are the effects of shielding on the magnetic fields?

The reflection and absorption
B Reflection and tunnel effect
C. Absorption and tunnel effect
D reflection and increased propagation speed

9 What is the most appropriate equipment to make the measurement of the phase difference between two sinusoidal signals?
The Wattmeter
B Oscilloscope
C FREQUENCY
D standing wave meter

10 As describe the figures which represent an oscilloscope the phase relationship between two sinusoidal signals?
The figures Lissajous
B Figures Dirac C merit Figures Figures D Watt



11 What kind of ideal circuits have the signal current and voltage phase?

Purely capacitive circuits B purely resistive circuits purely inductive circuits C
D Any type of circuit, be it purely capacitive, purely resistive or purely inductive

12 It is said that two sinusoidal signals are quadrature?

When the gap between them is 0 degrees B When the gap between them is 60 degrees C. When the gap between them is 90 degrees
When the gap D between them is 180 degrees

13. The noise power is given by Pn = KTB As designates the constant k?

The Kelvin Constant
B Constant Lissajous
C Constant Dirac
D Constant Boltzmann

14 How can we reduce the noise power of a receiving system?

The increasing as much as possible the width of effective system bandwidth
B increasing as much as possible the noise temperature of the system, without degrading the desired signal
Filtering C in order to reduce as much as possible the width of the effective system bandwidth, without degrading the desired signal
D None of the above is correct

15 Thermal noise is a sign

A sinusoidal continuous B C D quadratic random

16 What do you mean FSK?

The "Frequency Shunt Kelvin" B "Frequency Shift Keying" C "Forward Shunt Keying" D "Forward Shift Keying"



17 When transmitting a data signal, why it is important to know what the appropriate duty cycle ( "duty cycle")?
A To help tune the transmitter
B To avoid any damage to the final stage output of the transmitter
C To allow other stations have time to stop transmission
D All options are valid

18 What kind of information can be transmitted through digital waveforms?

Human Voice
B video signals
C Data
D All options are valid

19 The bit rate may be defined as

The number of bits per second
B the error rate per bit transmitted
C the number of phase inversions in a given communication
D the amount of information associated with each transmitted bit

20 What parameter varies in the modulated signal in a pulse position modulation system commonly referred to as PPM ( "Pulse-Position Modulation")?
A The number of pulses per second
B The amplitude of pulses
The duration of the pulses C
D The time at which each pulse produces

21 that are associated with the CRC and FEC acronyms in electronic communications?

The A different analog and digital modulation techniques B The error detection system C Data transmission RF amplification systems
D The impedance matching systems



22 In a communication bit rate is 9600. Knowing that the baud rate is 4800, which the number of bits per symbol / word (bit set with fixed length)?
A 2
B 4
C 8
D 16

23 Which statement is correct?

The Duma general and for a given type of communication, the higher the lowest bit rate is the bandwidth required
In general shape and B for a given type of communication, the higher the bit rate, the greater the bandwidth required
C In general way and for a given type of communication, the width of necessary band does not depend on the bit rate
D Generally, for a given type of communication and for a given bit rate, the bandwidth required only depends on the power reflected by the antenna

24 Analog / digital conversion can be divided into three stages which are

The differentiation and integration sampling integration B, encoding and quantification C to sampling, quantization and coding the quantification of D, sampling and integration

25 The Nyquist or sampling theorem states that

The sampling frequency must be at least equal to the most frequently associated with the sampled signal
B the sampling frequency should be at least twice the highest frequency associated with the sampled signal
C the sampling frequency should be at least four times the most frequently associated with the sampled signal
D sampling frequency should be at least ten times the most frequently associated with the sampled signal

26 In an analog / digital conversion that is the "aliasing"?

The distortion is the result of not using quality components on circuit
B is a random distortion which occurs in the conversion of very high frequency signals
C is a distortion associated with nonlinearities the amplifiers used in the process
D is the distortion resulting from non-compliance with the Nyquist theorem



27 The convolution of two rectangular pulses results in

To a rectangular pulse
A triangular pulse B
C an infinitely amplitude pulse
A D-zero-amplitude pulse

28 Response of a capacitor to an AC?

A As you increase the frequency of the alternating current applied to reactance decreases B As you increase the frequency of the alternating current applied to reactance increases C. As you increase the amplitude of the alternating current applied to reactance increases D As you increase the amplitude of the applied AC reactance decreases

29 a capacitor constituted by two flat metal surfaces, separated by an insulator increases as its capacity
The increased area of ​​the metal surfaces
B reduces the distance between the metal surfaces
C increases the dielectric constant of the insulating
D All answers are correct

30. The reactance of a capacitor is increased as

The lower your greatest B capacity for its smaller capacity C is its largest D inductance is its inductance

31 What is the reactance in a coil?

The Opposition to direct current flow caused by the resistance
B opposition to the alternating current flow caused by its inductance
C A property ideal resistors in AC circuits
D production of a large spark in the switch contacts when the coil power supply is turned off

32 Which of the following statements is correct?

The a coil, as it increases the frequency of the alternating current applied reactance decreases B a coil, as it increases the amplitude of the alternating current applied reactance increases C. in a coil, as it increases the amplitude of the alternating current applied reactance decreases
D a coil, as it increases the frequency of the applied AC reactance increases



33 The quality factor (Q) of a coil is much greater

Most as is its parasitic resistance
B the smaller its parasitic resistance
C the lower its removal to circuit physical limits in which it operates
D greater their departure to the circuit physical limits in which it operates

34 As two coils must be positioned so as to minimize the mutual inductance?

A With its winding axis aligned
B with their winding axes parallel to each other
C with their winding axes perpendicular to each other
D Both shielded in the same shielded space, regardless of the relative orientation of their axes

35 The value of the coefficient of self-induction coil is a cylindrical greater the

The larger the internal resistance of the coil
B greater the capacity of the coil windings
C major is the number of coil windings
D All of the above assumptions are correct

36 The value of the coefficient of self-induction of a cylindrical bobbin depends, among other factors,

The number of turns and the magnetic permeability of the material which constitutes the core
B the number of turns and resistance associated with this coil
C magnetic permeability of the material that constitutes its core and capabilities between its turns
dielectric constant of the material D which constitutes its core and capabilities between its turns

37 In an ideal transformer which the relationship between the primary power (power supplied to the transformer) and the secondary (power provided by the transformer to the circuit that you want to feed)?
The same St.
B is the primary power greater than the power of the secondary
C. The power of the secondary is greater than the power of the primary
D is not possible to establish this relationship because it depends on factors that are not known



38 that part of the transformer normally connects the power source?

A When the transformer secondary
B When the transformer primary C When D transformer core plates At transformer

39 The primary of a transformer with 100 turns is traversed by a current of 10 A. What is the current in the secondary of the transformer if it has 1000 turns?
The 1
The B 10
C 100 A
D 0.1 A

40 What is the voltage in the secondary 500 windings of a transformer if the 2250 primary windings of the transformer has an AC voltage of 120 V?
The 2.37 kV
B 540 V
C 26.7 V
D 5.9 V

41 is intended to adapt a circuit whose output impedance is 15 Ohms, to the input of an amplifier whose input impedance is 50 ohms. What should be the relationship between the number of turns in the primary and secondary impedances of the transformer?
The The number of turns in the secondary must be larger than the number of turns in the primary B The number of turns on the primary must be larger than the number of turns on the secondary is the number of turns of the primary must equal the turns number of the secondary
D None of the above hypothesis is correct because a transformer can never serve as transformer impedances

42 A "display" seven segments may be Constructed with a particular type of diode. What kind of diodes refer to?
The diodes varicaps B Diodes Schottky Diodes LED C
D Zener Diodes



43 What is a varicap?

The is a diode that emits light
B is a commonly used in diode rectifier bridges
C is a diode having a high switching speed
D is a diode with variable capacity according to the voltage applied to it

44 When that occurs in reverse bias of a diode?

The Reverse biasing of a diode occurs when the anode is subjected to a positive potential relative to the cathode
B reverse bias of a diode occurs when it is installed on top of a printed circuit
C A reverse bias of a diode occurs when it is installed on the bottom of a printed circuit
D reverse bias of a diode occurs when the cathode is subjected to a positive potential relative to the anode

45 What is leakage current in a bipolar diode germanium?

The current is passing through the diode at very high frequencies due to parasitic capacitive effects B is the current through the diode at very low frequencies due to inductive parasitic effects C is the current through the diode when it is reverse biased
D is the current through the diode when it is directly polarized

46 Which of these describes the construction of a MOSFET transistor?

Port A is formed by a reverse voltage junction
B The door is separated from the channel by an insulating thin layer C The source is separated from the drain by an insulating thin layer D The source is formed by metal deposition on silicon

47 Which of these is a useful test for a silicon NPN transistor, wherein the PN junction is forward biased?
Measuring the resistance between the base and emitter with an ohmmeter - the measure should be approximately 6 to 7 ohms
B Measuring the resistance between the base and emitter with an ohmmeter - the measure should be about 0.6 to 0.7 Ohm
C Measure the voltage between the base and emitter with a voltmeter - the measure should be about 6-7 Volt
D Measure the voltage between the base and emitter with a voltmeter - the measure should be about 0.6 to 0.7 Volt



48 What is the beta of a bipolar junction transistor?

In the frequency at which the current gain is reduced to 1
B The collector current of the variation in the base current
C In the rupture voltage of the base-collector junction
D In transistor switching speed

49 What does the acronym CMOS?

The Common Mode Oscillating System
B Complementary Mica-Oxide Silicon
C Complementary Metal-Oxide Semiconductor
D Complementary Metal-Oxide Substrate

50 How do you compare the DC input impedance at the gate of a field effect transistor (FET) with the DC input impedance of a bipolar transistor?
The can not be compared without knowing the source voltage value
B FET has a low input impedance; the bipolar transistor has a high input impedance FET C has a high input impedance; the bipolar transistor has a low input impedance D The input impedance of a FET is equal to that of a bipolar transistor

51 What is the advantage of CMOS logic devices over TTL devices?

The differential output capacity
B Low distortion
C Immune to damage from static discharge
D Low power consumption

The assembly 52 in common emitter characterized by the following configuration:

The sender's mass (in AC) input signal between the base and the emitter, and the output signal between the collector and the emitter (mass)
B manifold mass (in AC) input signal between the base and the emitter, and the output signal between the transmitter and the mass
C based mass (in AC) input signal between the transmitter and the base and output signal between the collector and the base (mass)
D None of the above is correct



The assembly 53 with a transistor, designated as the "emitter follower" (or "common collector"), is characterized by having
The unity gain
B high input impedance
C low output impedance
D All of the above answers are correct

54 What is the main function of a shielding grid in a vacuum tube?

The reduction of the capacity between the grid and the plate
B Increased efficiency
C Best high-frequency response
Plate D resistance Reduction

55 In a theoretically ideal OPAMP as the gain varies with frequency within its range of operating frequencies?
The increases linearly with increasing frequency
B decreases linearly with increasing frequency
C decreases logarithmically with increasing frequency
D does not vary with frequency

56 What is the voltage output of the circuit of Fig wherein R1 = R2 = 1000 ohms and 10,000 ohms, the entrance a 0.23 V voltage is applied?

0.23 V
B 2.3 V
C -0.23 V
D -2.3 V



57 What is an operational amplifier?

The A high gain differential amplifier whose characteristics are determined by the external components to the amplifier
B An audio amplifier whose characteristics are determined by the internal amplifier components
C An amplifier used in the power stage of an FM transmitter of the amateur service in the 10 GHz band
D A program which calculates the gain of an RF amplifier

58 which normally is the input impedance of an OPAMP integrated circuit?

The 100 Ohm
B 1000 Ohm
C Very low
D Very High

59 What is the equivalent capacity of two capacitors of 5000 pF and a capacitor of 750 pF all connected in parallel?
The 576.9 pF
B 1733 pF
C 3583 pF
D 10750 pF

60 What is the inductance of three coils 10 mH connected in parallel?

0.33 H
B 3,33 H
C 3,33 mH
D 33 mH

61 What is the capacity of a 20 microfarad capacitor connected in series with a capacitor of 50 microfarads?
A 70 nF
B 14.3 MFD
C 70 microfarad
D 1 mF



62 What should add the component is a coil to increase the inductance of the loop?

The A capacitor B connected in series resistance connected in parallel A C A coil connected in parallel
D A coil connected in series

63 The real condenser (so not ideal) can be modeled by a combination of three ideal components. What are these components?
The ideal condenser, ideal coil and ideal strength B ideal condenser, ideal coil and ideal transistor C condenser ideal, ideal strength and ideal diode D Condenser ideal, ideal diode and ideal transistor

64 The capacitive parasitic effects between the turns of the real coils (therefore not ideal) manifest more
The direct current
B at higher frequencies
C at lower frequencies
D No answer is correct because these effects never manifest

65 What is the effect caused by parasitic capacity between the turns in a coil?

The The magnetic field reversal can undergo a
B The coil may acquire own resonance at certain frequencies
C The magnetic permeability may increase
D The nominal voltage can be exceeded

66 What is the voltage drop at the terminals of a connection in series of two silicon junction diodes?

It is about half the voltage in each
B is about twice the voltage drop in each
C has a fixed value (regardless of the current in the circuit) of approximately 25 V
D has a fixed value (regardless of the current in the circuit) of about 12.5 V



67 Which of the following is an undesired effect of using a too wide bandwidth filter in the IF section of a receptor?
The "Overshoot" (over-pass) "offset" output
B filter timbre Sound
C distortion by thermal noise
D One can capture unwanted signals

68 What is the bandwidth at -3 dB of a resonant circuit in parallel with the resonant frequency of 7.1 MHz and the Q factor = 150?
The 157.82 Hz
B 315.66 Hz
C 47.33 kHz
D 23.67 kHz

69 How often approximate resonance of a circuit RLC series is R = 22 ohm, L = 0.05 mH and C = 40 pF?
The 44.72 MHz
B 22.36 MHz
C 3.56 MHz
D 1.78 MHz

70 What is the resonance frequency of a parallel RLC circuit if R = 47 Ohm, L = 0.025 mH and C = 10 pF?

The 10.07 MHz
B 63.24 MHz
C 10.07 kHz
D 63.24 kHz

71 The quality factor (Q) of a passive filter with a given resonance frequency (fr) is greater

The greater the bandwidth (B) at -3 dB
B greater the number of transistors with gain greater than 0 dB
C the smaller the bandwidth (B) at -3 dB
D smaller the number of transistors with gain greater than 0 dB



72 Which of the following has a network with T series capacitor and a shunt coil (shunt) in parallel?
The Transforms impedances and is a low-pass filter B transforms reactance and is a low-pass filter C transforms impedances and is a high-pass filter
D transforms reactance and is a narrow band notch filter

73 quartz crystal filter is characterized by

The have a high quality factor (Q)
B have a bandwidth (B) very narrow
C having a good temperature stability
D All of the above assumptions are correct

74 What is the value of the impedance of a circuit RLC series resonance?

The high compared with the circuit resistance
B Approximately equal to the capacitive reactance
C approximately equal to the inductive reactance
D approximately equal to the circuit resistance

75 What is the phase relation between current and voltage through a parallel resonant circuit?

The The voltage has a 90 ° advance relative to the current B chain has a forward 90 ° from the voltage C voltage and current are in phase
D The voltage and current are in phase opposition

76 What is the value of the impedance of a circuit with a resistance, a coil and a capacitor all in parallel, at resonance?
Approximately equal to the circuit resistance
B Approximately equal to the inductive reactance
C reduced in comparison with the circuit resistance
D approximately equal to the capacitive reactance



77 What is the advantage of a power supply switched to a relatively linear power supply?
The switching power supply allows the higher output voltage values
The switching power supply B involves a lower number of components in the circuits
The C source switched by operating at higher frequencies allows the use of smaller circuit components
D All options are valid

78 Which of the following is presented by a linear electronic voltage regulator?

The output voltage ramp
B A faster switching allows higher output voltage values
C. The duty cycle of the control element is proportional to the line load conditions or
D conduction control element is varied to maintain constant the output voltage

79 Which device is often use as a voltage reference in a stable linear voltage regulator?

The A zener diode
A tunnel diode B
C A silicon controlled rectifier
D varicap diode or a varactor

80 What is the purpose of Q1 in the circuit of Figure?
A provides negative feedback to improve the regulation
B provides a constant load to the voltage supply regulator is C or D control element of the circuit provides current to D1



81 What is the purpose of C1 in the circuit of Figure?
The contributes to the resonance circuit to the input frequency
B provides a fixed bias Q1
C filtered output
D controls the output voltage

82 What is the purpose of R2 in the circuit of Figure?
The provides a fixed bias to Q1 B provides a fixed bias D1 C Reduces noise in D1
D provides a constant minimum load Q1

83 What is the main disadvantage of switching power supplies in relation to linear sources?

The Lower income
B Need for greater heat dissipating plates
C Generating more electromagnetic noise
D Increased physical volume for the same power

84 What is the safety factor provides a drainage resistance of the power source?

The works as fuse excess tension
B unloads the smoothing capacitor
C Excludes the risk of electric shock produced by induction coils
D Deletes the current "loop" of land



85 What kind of capacitor is typically used in power supplies to filter the rectified signal alternating current?
The disc ceramic capacitor B vacuum variable capacitor C Condenser mica
D Electrolytic Capacitor

86 In a class B amplifier

The transistor conducts during a fourth period
B transistor conducts during half-time
C transistor leads for three quarters of the period
D transistor conducts during the whole period

87 What is the advantage of a class C amplifier?

High efficiency
B linear operation
C does not require tuning circuits
D All options are valid

88 In a class AB amplifier

The transistor conducts for less than a half period
B transistor conducts during half-time
C transistor conducts for more than half period
D transistor conducts during the whole period

89 In a class A amplifier

The transistor conducts for less than a half period
B transistor conducts during half-time
C transistor conducts for more than half period
D transistor conducts during the whole period

90 Which of the following types of amplifiers characterized by having a dead zone of operation that causes crossover distortion ( "crossover distorsion")?
The Amplifier "push-push" B Amplifier "push-pull" C Class C
D Class A



91 The tuned amplifiers

The are only useful for amplifying optical signals
B are only useful for amplifying audio signals
C are useful for amplification of broadband signal
D are useful for the amplification of narrowband signals

In Figure 92, the purpose of which R1 and R2?

The load resistors
B Polarization fixed
C filtering high frequency components
D Feedback

93 What type of circuit is shown in Figure?

The voltage regulator with switch
B linear voltage regulator
C amplifier with common emitter
D amplifier emitter follower



94 Generally, the tuned amplifiers typically exhibit a response

The lowpass
B high-pass
C bandpass
D rejects band

95 Why is that the products of 3rd order intermodulation are one aspect of particular interest with regard to linear amplifiers power?
A Because of a general, are very close to the desired signal in terms of frequency
B For Generally, they are relatively distant from the desired signal in terms of frequency
C Because of a generally inverted sidebands, producing distortions
D Because of a generally maintain the sidebands, thus causing multiple signal duplication

96 The figure represents
A product detector
B is a frequency modulated detector
C one envelope detector
A phase detector D

97 What are the main advantages of a product detector on a envelope detector?

The detector The product is simpler than the envelope detector and generally has fewer discrete components
B The product detector behaves better on signs over-modulated and has a better signal / noise ratio that an envelope detector
C. The product detector demodulates all types of signals including digital signals simultaneously and performs error correction, the envelope detector does
D All alternative answers are wrong



98 What type circuit is used in different FM receivers to convert signals from an audio IF amplifier?
The detector product
B phase inverter
C detector engaging
D All alternative answers are wrong

99 What is a discriminator frequency?

The FM generator circuit A
B A circuit that filters two very close adjacent signals
C A circuit with automatic band switching
D A detection circuit FM signals

What 100 the basic components of an oscillator?

The An amplifier and a divider
A multiplier B and a frequency mixer
C A pump and a filter that works in a "loop" for feedback ( "feedback")
A D amplifier and a feedback circuit

101 What determines the frequency of an LC oscillator?

A The number of floors in the counter
B The number of floors in the divisor
C Inductance and capacity in the tank circuit
D takes the delay circuit

102 In electronics, of a general, as an oscillator circuit can be defined?

A is a circuit that generates a periodic signal from an external signal applied to it at a frequency ten times lower
B is a circuit that generates a periodic signal from an external signal is applied to it with double the frequency
C is a circuit that generates a periodic signal from an external signal is applied to it with the same frequency
D is a circuit that generates a periodic signal without the need of applying to an external signal



103 Oscillators active RC (with Operational Amplifier - OPAMP) should not be used for frequencies higher than 1 MHz (and ideally working frequencies should not exceed 100 kHz). Because?
Due to the parasitic inductances and resistances capabilities
B Due to parasitic inductances and resistances of the capacitors
C Because of limitations in response frequency of AMPlificadoes operating - OPAMP
D All alternative answers are wrong

104 As provided positive feedback to a Hartley oscillator?

A through an inductive divider
B Through a capacitive divider
C Through a coupled connection
D Through a neutralizing capacitor

105 As provided positive feedback to a Pierce oscillator?

Through the shunt coil
B Through a coupled connection
C Through a neutralizing capacitor
D Through a quartz crystal

106 What is a diode oscillator Gunn?

The An oscillator intended to operate in the negative resistance property of adequately doped semiconductor
B An oscillator based on a diode argon gas
C A very stable reference oscillator based on the principle "tee-notch"
D A very stable reference oscillator based on hot carrier effect

107 What is a VCO?

The controlled oscillator is a frequency
B is a voltage controlled oscillator
C is an oscillator controlled by a coherent light signal
D is a controlled oscillator by a gravitational field



In a spectrum analyzer 108 which translates the phase noise with respect to an "ideal" to the output carrier of a transmitter?
The signs in very concentrated around the carrier, a little above and a little below this
In B signals in exact multiple frequency carrier
In C signals whose frequencies depend not only on the carrier frequency and the frequency of the transmitter signals on the vicinity concerned
D signals whose frequencies are related to the carrier frequency in a relation that results from the Fibonacci sequence

109 Generally, that is a phase locked loop PLL ( "Phase Locked Loop")?

A is a mesh in which the feedback signal is used to synchronize the frequency (or phase) of the instantaneous output signal with the frequency (or phase) of the instantaneous input signal
B is a mesh in which the feedback signal is used to increase the instantaneous power of the output signal in proportion to the instantaneous power of the input signal, always ensuring that these two signals are in phase
C is a loop in which the feedback signal is used to minimize the instantaneous frequency of the output signal as a function of a phase voltage applied as an input signal
D is a loop in which the feedback signal is used to maximize the instantaneous frequency of the output signal as a function of a phase voltage applied as an input signal

Which of the following circuits 110 may not be part of the block diagram of a phase locked loop?
The VCO
B envelope detector C phase comparator D Low Pass Filter

111 What advantage is obtained with the use of a digital signal processor (DSP), an amateur station?

The Good earthing
B Suppression of noise signals received
C Increased antenna gain
D Increased bandwidth of the antenna band

112 In the digital signal processing, are often used filters that are called by FIR. What is this acronym?
The "Filter, Infinite, Radio"
B "Forward Impulse Radio"
C "Fiiter of Impulse Response"
D "Finite Impulse Response"



113 In the digital signal processing, are often used filters that are called by IIR. What is this acronym?
The "Infinite Input Radio"
B "Infinite Impulse Radio"
C "Infinite Impulse Response"
D "Input Impulse Response"

114 Duma simplified way we can say that the result of the Fourier transform

A is the representation in the frequency domain S (f) of a signal whose representation in the time domain is s (t)
B is the representation in the time domain s (t) of a signal whose representation in the frequency domain is S (f)
C is the representation in the field s timeline (x, y, z, t) of a signal whose representation in the frequency domain is S (f)
D is the representation in the complex s domain (i) of a signal whose representation in the real domain is S (r)

115 The Fourier transform of a periodic signal

A is a sign similar to white Gaussian noise
B is composed of square waves overlaid
C consists of pulses in the harmonic signal frequencies
D is a sinusoidal wave, whose frequency is inversely proportional to the largest period of the signal transformed

At a receiver 116, so that the signals are adjusted to maintain an average output level at approximately constant circuits must be used
The stabilized power
B automatic gain control
C low noise amplifiers
D crystal frequency synthesizers



117 What type of circuit is shown (where A is an operational amplifier, R1 and R2 are resistors, and D1 and D2 are diodes)?

The PLL
B VCO
C limiter
Power supply D

118 As a measure of 20 dB over S9 read in S meter compares to an S9 signal, assuming a proper calibration of the S meter?
A is 10 times fainter B is 20 times fainter C is 20 times stronger D is 100 times stronger

119 To what extent is that the decrease in afeita noise factor performance of the receiver?

The reduces the signal to noise ratio
B increases the signal-to-noise ratio
C reduces the bandwidth
D increases the bandwidth

120 As can be defined in a simplified way, the concept of selectivity of a receiver?

The is the ability of the receiver must reject signals at frequencies very close to the required bandwidth of the useful signal
B is the capacity that the receiver must demodulate very weak signals
C is the capacity of a receiver must demodulate signals using digital modulation techniques
D is the ability of a receiver must reject noise from the power source of the receiver itself



121 What is the relationship between noise factor and the noise figure?

The noise figure is a noise factor in dB
B The noise figure is the factor of noise multiplied by the signal to noise ratio at receiver AC noise figure input is the noise factor multiplied by the signal-to-noise outside the DA noise figure receiver is the noise factor expressed in Hz

122 As means the process whereby signals from two transmitters are mixed in one or both end amplifiers and generate unwanted signals at the sum and difference frequencies of the original signals?
The Desensitization amplifier
B Neutralization
C Lock
D Intermodulation

123 As is known to reduce the sensitivity of the receiver caused by a strong signal near the received frequency?
The desensitization
B Muting
C Interference cross modulation
D "Squelch gain rollback"

124 How it can reduce desensitization odds receiver?

The Decreasing the width of RF receiver B band Increasing the intermediate frequency of the receiver C Increasing the gain "front-end" of the receiver
D Passing AGC fast to slow

125 Generally, a frequency modulation is

A rotational frequency
B an addition of the modulating frequency by the inverse of the carrier frequency period
A frequency-translation C
D None of the hypotheses is correct



126 What is the phrase that is true?

The modulation is the signal sampling at its base band
B The modulation is reflected in the translation of a signal of a frequency range to another frequency range
C In a modulation process there is never any translation frequencies
D modulation translates into rotation a sign of its frequency range in real space to another frequency range in the complex space

127 Why is it that the radio signals are not issued in their baseband, lacking a translation resulting frequency modulation process?
A Because of a general, baseband signals could never be recovered
B For Generally, the base band most signals to be transmitted, is located in the area not suitable for radio spectrum
C Because of a general, the translation frequency is essential for the implementation of error correction techniques in analog modulation
D None of the answers is correct

128 Which of the following is a reason to use an impedance adaptation transformer?
To maximize the signal to noise ratio in the issue
B To maximize power transfer
C To maximize the standing wave coefficient
D To maximize the gain of the output amplifier

The phase modulation 129

A is never used in radio
B as the modulation frequency, is a frequency modulation type
C as amplitude modulation is demodulated using an envelope detector
D is expressly prohibited the applicable national regulations

130 Which of the following types of modulation means a modulation phase?

PSK FSK B C D ASK QAM



131 The crystal filters

The have their resonance frequency easily changed by adjusting the potentiometers that are an integral part of its crystals
B have a low Q
C for the same order, they are cheaper than those made of coils and capacitors
D have a high Q

The final stage 132, Class C amplifier, a frequency modulated transmitter can, in a simplified way, be divided into three parts:
The input adaptation mesh, amplification transistors and mesh output adjustment
B Mesh input adaptation, amplification transistors and output PLL loop with C input mesh with VCO, transistor amplification and output adaptation mesh D input mesh with VCO, amplifier transistors and output loop with PLL

133 What is the total bandwidth of an FM telephony transmission with 3 kHz deviation and maximum modulation frequency of 2.5 kHz?
The 3 kHz
B 11 kHz
C 8 kHz
D 16 kHz

134 Why you should not use the frequency modulation for voice below 29.5 MHz?

The emitter efficiency is reduced in this mode
B can not attenuate harmonic frequencies to practical levels
C The bandwidth exceeds the recommended limits
D The stability of frequency would not be appropriate

135 What is the main disadvantage of using amplifiers in class C?

The High harmonic distortion
B Low efficiency
C High noise
D Class C presents no disadvantage compared to other amplifier classes

136 Generally, the phase noise is expressed in

The dBc / Hz B dBc / V C dBc / W D dBc / Ph



137 Where the ceilings for acceptable for spurious emissions in the amateur service can be found?
In the manual of the transmitting antenna manufacturer
B The applicable Recommendation CEPT
C The label on the back of the emission equipment
D There are no ceilings for emissions in the amateur bands can not, under any circumstances, issue Spurious

138 What is the main advantage of using amplifiers in class A?

The Low Harmonic Distortion
B High efficiency
C Low linearity
The class D shows no advantage over other classes amplification

139 Generally, satellite dishes are most widely used in

LF
HF B C D VHF SHF

140 What should be approximately the physical length of a half-wave dipole antenna adjusted to a frequency of 3.55 MHz?
A 12 m
B 25 m
C 40 m
D 80 m

141 What is the main advantage of a dipole folded dipole relative to Hertz?

The occupies less space and is easier to install
B has higher impedance, making it easier to adapt to the sender
C has higher directivity, which allows its use in the amateur communications satellite above 30 GHz
D All the hypotheses are correct



142 How varies the gain of a satellite dish with a doubling of operating frequency?

The The gain does not vary
B Gain is multiplied by 0.707
C The gain 6dB
D The gain 3dB

143 What it is approximately the impedance of the feeding point in the center of a folded dipole antenna?
300 Ohm
B 6.28 times the operating frequency
C 50 Ohm
D 1450 Ohm

144 How is called the ratio of the power radiated by the antenna and the power delivered to it?

The antenna radiation gain
B antenna radiation directivity
C antenna radiation efficiency
The antenna width D of the radiation beam

145 varies as the beam width of an antenna with increased gain?

The increases geometrically
B increases arithmetically
C is maintained essentially unchanged
D Decrease

146 The radiation efficiency of an antenna can be expressed as the ratio between

The radiation resistance and loss resistance of the antenna
B radiation resistance and the total resistance of the antenna
C loss resistance and radiation resistance of the antenna
D total resistance and loss resistance of the antenna



147 Which of the following statements is correct?

The Antenna is a reciprocal element, ie its operating principle is identical in emission and reception
B The antenna is a reciprocal element, ie its operating principle makes both radiate in the horizontal plane and in the vertical plane
C The antenna is not a reciprocal element, ie its operating principle gives it different characteristics in the emission and reception
D The antenna is not a reciprocal element, ie its operating principle makes much less radiate in the horizontal plane than the vertical plane

148 If one dipole half-wave resonance at a given frequency is physically shortened, its impedance for this frequency,
The becomes capacitive
B becomes Inductive
C remains purely resistive
D All options are incorrect

149 What are the components of the total resistance of an antenna?

Radiation resistance and wave characteristic strength
B Resistance losses and resistance dipole
C resistance losses and wave characteristic strength
D radiation resistance and loss resistance

150 The isotropic antenna

It is used in the above 1 GHz communications
B is used for communications below 30 MHz
C is rarely used because it has side lobes in the radiation diagram are difficult to model theoretically
D has no physical existence serving only as a reference model

151 How can you improve the efficiency of a vertical antenna HF quarter-wave grounded?
A Installing a good radial system of land
B Isolating the shield of the coaxial cable of the earth
C Shortening the antenna vertically
Reducing the diameter D of the radiating element



152 In the antenna radiation pattern of the figure, which is the approximate ratio front / back?

A 10 dB
B 20 dB
30 dB C
D 40 dB

153 A real omnidirectional antenna

The presents an omnidirectional radiation pattern in all planes
B is in essence an isotropic antenna
C can be used only below 30 MHz
D presents an omnidirectional radiation pattern in a given plane

154 When the polarization of a receiving antenna is not the same as the polarization of the incident electromagnetic wave (that want to receive), one says that
A mismatch exists polarizations
B that the electric field and the magnetic field of the incident wave are in phase
C that the electric field and the magnetic field of the incident wave are quadrature
D there is a prevalence of foil polarization effect

155 What is the polarization of an electromagnetic wave if the magnetic field is parallel to the surface of the earth?
Circular
B Horizontal
C Elliptical
D Vertical



156 What is the cutoff frequency in waveguide?
The is the maximum frequency at which there is propagation in the waveguide
B is the frequency below which no propagating in waveguide
C is the frequency whose wavelength corresponds to the length of the waveguide
D is the frequency for which propagation speed in the waveguide is about half the speed of light in vacuum
157 What is a "balun"?
The is a device that allows the interconnection between stations installed in balloons and non-satellite
geostationary
B is a device that allows the interconnection between the output of the transmitters and coaxial cables
C is a device that allows the interconnection between balanced and unbalanced elements
D is a device that enables interconnection between the various parasitic elements of a Yagi

158 What is the velocity factor of a transmission line?

The consists of the ratio between the characteristic impedance of the line terminating impedance and
B Consite the shielding rate of the coaxial cable
C consists of the speed of the wave in the transmission line multiplied by the speed of light in vacuum
D is the ratio between the speed of the wave in the transmission line and the speed of light in vacuum

159 A coaxial cable is an element

What it is a constituent part of a waveguide
B balanced
Unbalanced C
D is a constituent part of a dipole Hertz

160 Dune generally varies as the attenuation of a coaxial cable as it increases the frequency of the transmitted signal?
The attenuation is independent of frequency
B Increase
C Decreases
D reaches a maximum close to 18 MHz



161 What is the physical length of a coaxial transmission line that has the electrical level of the 1/4 wavelength at the frequency of 14.1 MHz (for a speed factor of 0.66)?
The 20 m
B 2,3 m
C 3.5m
D 0.2 m

162 As means the ratio between the actual velocity of a signal on a transmission line and the speed of light in vacuum?
Speed ​​Factor
B Characteristic impedance
C Surge Impedance
D standing wave coefficient

163 What is the minimum number of discrete components (coils and capacitors) using the tuners antenna circuits "T" and "Pi"?

The topology "T" needs a minimum of three components and topology "Pi" need a minimum of four components
B Both topologies require at least two components
C Both topologies require at least three components
D topology "T" needs a minimum of three components and topology "Pi" needs a minimum of five components

164 What kind of reception equipment is desirable for communications via lunar reflection?

The equipment of high bandwidth
B very low dynamic range equipment
C Equipment with very low gain
D low-noise equipment

165 As means the layer formed occasionally in the region E?

The Transitional and Temporary B AND C AND D Sporadic Occasional E



166 a terrestrial connection, using the model of free space propagation, the power at the reception antenna is
The inversely proportional to the distance that separates the transmitting antenna
B inversely proportional to the square of the distance that separates the C transmitting antenna directly proportional to the square of the distance that separates it from D transmitting antenna directly proportional to the distance that separates it from the transmitting antenna

167 When referring to radio waves, which of the following statements is correct?

The attenuation caused by atmospheric gases and rain significantly affects the spread below 1 GHz
B The attenuation caused by atmospheric gases and rain is independent of the working frequencies, affecting all equally
C attenuation caused by atmospheric gases and rain affects significantly the spread above 10 GHz
D attenuation caused by atmospheric gases and rain affects significantly the spread below 30 MHz

168 As they designate critical frequency of the E layer of the ionosphere?

FCE
B Fee
C FSO
D FLE

169 The satisfactory receipt of communications in the bands of amateur service and amateur satellite depend on the signal / noise ratio. Which of the following types of noise should be considered?
The noise of the receiver (internally generated)
B atmospheric noise
C cosmic noise
D All the hypotheses are correct

170 a point to point connection, as it can increase the horizon radio?

The By increasing the power station
B By filtering on reception, particularly if they are located in areas with high thermal noise
C By increasing the height of the towers supporting the antenna emission and reception
D Cooling of receiving equipment, if they are located at altitudes above 800 m



171 What is the solar flux index?

Measure the highest frequency needed to ionospheric propagation between any two points on Earth
B Measurement of solar activity in the 28 MHz band
C Another name by which it is known the number of sunspots
D measurement of solar activity in the range of 2.8 GHz

172 In that consist geomagnetic disturbances?

The sudden fall of the solar flux index
B Earth's Magnetic Pole Shift
C Ripples in ionospheric layer
D Significant change of the earth's magnetic field in a short period of time

173 Unlike HF bands VHF and UHF bands are often used for satellite communications because

The electromagnetic waves associated with frequency VHF and UHF are little affected by the ionosphere on their way to and from the satellite
B the frequency changes by the Doppler effect caused by satellite movement are much smaller in VHF and UHF than at HF
C satellites are moving too fast to be followed by waves of HF
D is the Doppler effect causes the HF wave undergoes a translation in frequency to SHF, making it difficult reception signal

174 Which of the following advantages for radio results from periods of high geomagnetic activity?
Aurora reflecting VHF signals
B Higher intensity of HF signals to pass through polar regions
C Improving the spread of long-distance high-frequency signals
D Reduction of long delay echoes

175 What is the range that allows better chances of a good connection, if the maximum usable frequency (MUF) between two stations is 22 MHz?
The 28 MHz
B 21 MHz
C 14 MHz
D 7 MHz



176 What measures should be taken to obtain a low attenuation in HF transmissions?

The Select an immediately lower frequency to the maximum usable frequency (MUF) B Select an immediately higher frequency than the usable minimum frequency (LUF) C Select an immediately lower frequency to the critical frequency
D Select an immediately higher frequency than the critical frequency

177 a radio link, it is found that there is a variation in signal level on the receiving time, even if power is constant. What name is given to this phenomenon?
Attenuation in free space
B Fading
C Synchronous Variation
D All of the above assumptions are incorrect

178 What does the acronym LUF?

The "Lowest Usable Frequency"
B "Longest Usable Function"
C "Lowest Universal Frequency"
D "Longest Universal Function"

179 What happens to the spread of HF where the usable minimum frequency (LUF) exceeds the maximum usable frequency (MUF)?
A You can not keep HF communications on the route concerned
B improves the quality of the propagation path in the whole range HF
The spread C double jump (double hop) becomes more frequent in the route
D All of the above assumptions are incorrect

180 In communications on shortwave, what is the meaning of Acronym NVIS?

The "Narrow Vertical Incidence Skywave"
B "Near Vertical Incidence Skywave"
C "Near Vertical Incidence Source"
D "Narrow Vertical Incidence Source"

181 What does "critical angle" in the context of propagation of radio waves?

The A long journey oriented azimuth of a distant station
B A short path oriented in azimuth of a distant station
C The smallest starting angle that returns a radio wave to earth under specific ionospheric conditions
D The biggest departure angle that returns a radio wave to earth under specific ionospheric conditions



182 As means the distance measured at the Earth's surface between the antenna base and the point where the beam emitted by the antenna touches the surface of the earth?
Geo radio
B maximum beam distance
C Horizon Radio
D Intersect radio

In a terrestrial link 183, wherein the first Fresnel ellipsoid is clear, the attenuation between the two stations involved in binding
A is much smaller than the free space attenuation
B is much larger than the free space attenuation
C is roughly equal to the attenuation in free space
D There is no relationship between the unblocking of the first Fresnel ellipsoid and signal attenuation in the connection between the two stations

184 In a radio link, the attenuation in free space is increased as

The higher the B minor issue of power is the smallest C bond distance is the frequency
D major is the frequency

185 What is the average power measured in RF complete cycle with a peak voltage of 30 V on a resistive load of 50 Ohm?
The 4.5 W
B 9 W
C 16 W
D 18 W

186 What is the advantage of using a peak reading power meter to monitor the output of a single sideband telephony transmitter?
The facilitates the determination of the correct tuning of the output to the circuit
B Displays the peak power values ​​surrounding the output more accurately in the presence of modulation
C facilitates the detection of high standing wave ratios in the feed line
D allows the determination of the presence of waves with "flat-topping" modulation peak times



187 If a frequency counter with an accuracy of ± 0.1 ppm register 146,520,000 Hz, what is the maximum difference between the actual measured frequency and the respective reading?
The 14.652 Hz
B 0.1 kHz
C 1.4652 Hz
D 1.4652 kHz

188 In order to minimize the error in a measurement voltage, a voltmeter having an internal impedance should

The as low as possible, ideally close to zero
B as high as possible, ideally tending to infinity
C of the same order of magnitude of the circuit impedance to measure
D All of the above assumptions are incorrect because of an internal impedance voltmeter has no effect on the measurement error

189 is intended to measure the rms voltage of a square wave, 10 MHz the value of the main frequency. Featuring up four rms measuring equipment exactly the same, differing only in the maximum frequency of operation:. 1 MHz, 10 MHz, 20 MHz and 100 MHz What equipment should be used?

The Equipment whose maximum operating frequency is 1MHz, because most of the energy situation of the frequency signal is below this
B The equipment with a maximum operating frequency is 10 MHz, as there is resonance and measurement is the most correct
C Whether you can use the equipment with a maximum operating frequency is 20 MHz, as the equipment with a maximum operating frequency is 100 MHz, because the error is exactly the same
D Equipment with a maximum operating frequency is 100 MHz, for the error associated with the measurement is the smallest of the four cases

190 What test equipment includes amplifiers in the system of horizontal and vertical system?

The Ohmmeter
B signal generator
C Ammeter
D Oscilloscope

191 In its operation a 'dip-meter "uses

A diode bridge
A directional coupler B
C a variable-frequency generator
D a DC generator with variable amplitude



192 To that effect can an antenna impedance meter be used?

To determine the antenna gain in the FBI
B For pre-tune an antenna tuner
C To pre-tune a linear amplifier
D To determine the antenna system line losses

193 Which of the following statements is correct?

The A spectral analyzer measures ionospheric reflection; an oscilloscope presents graphically the electrical signals
B A spectrum analyzer shows the amplitude peaks of the signals; an oscilloscope displays the average amplitude of signals
C A spectrum analyzer shows the signals in the frequency domain; an oscilloscope displays signals in the time domain
D A spectrum analyzer displays radio frequencies; an oscilloscope presents audio frequencies

194 Which of the following test instruments is used to display the distortion products of intermodulation in a transmission in single sideband at a certain distance from the transmitter?
The A wattmeter
B A spectrum analyzer
C A logic analyzer
D A time domain reflectometer in

195 In that domain signals on an oscilloscope are displayed?

In the frequency domain
B In the logical domain
C On space
D In the time domain

196 Which of the following is a very important precaution to take when connecting a spectrum analyzer to the output of a transmitter?
Using the coaxial cables of high quality double shield
B attenuate the output signal from the transmitter that is provided to the spectrum analyzer
C adapt the transmitter output impedance to input impedance of the spectrum analyzer
D All options are valid



197 That power is absorbed by the load a directional power meter connected between a transmitting terminal and a load register a reading of 100 W of power transmitted and reflected 25 power W?
100 W
B 125 W
C 25 W
D 75 W

198 What measuring equipment must be connected to the marshland of receiving antenna to get an idea of ​​the signals that are received at that antenna?
The A signal generator
B A wattmeter
C A spectrum analyzer
D An oscilloscope

199 As is known blocking a telephony signal FM for other telephony signal FM stronger?

The desensitization
B Interference cross modulation
C Capture Effect
D Discrimination frequencies

200 What causes intermodulation in an electronic circuit?

The A gain too low
B Lack of neutralization
C circuits or nonlinear devices
D positive feedback

201 In radio systems the blocking effect occurs

A transmitter in
The receiver B
C equipment in the power supply
D in the final stage output filter of the transmitter's RF amplifier

202 intermodulation RF signals

The distortion is calculated as a linear
B is the same as the harmonic distortion
C is a modulation Interdigital
D is considered a non-linear distortion



203 In a communication I felt offended by the words addressed to me by an amateur colleague. What's more correct to do?
The Complaining me to ANACOM
B In a future communication that colleague intervene, talk about what happened in a cordial tone in the sense that similar situations do not happen again
C Complaining me to a police force
D not connect