NavigationUser loginWho's new
|
Amateur Radio Question PoolsNew! View the differences between the 2008 Extra question pool and the previous pool. Canadian Advanced Qualification Question PoolPrev 1 2 3 4 5 6 7 NextA-002-01-01 What two elements widely used in semiconductor devices exhibit both metallic and non- metallic characteristics? Silicon and germanium Galena and bismuth Silicon and gold A-002-01-02 In what application is gallium-arsenide used as a semiconductor material in preference to germanium or silicon? At microwave frequencies At very low frequencies In bipolar transistors A-002-01-03 What type of semiconductor material contains fewer free electrons than pure germanium or silicon crystals? N-type Bipolar type Superconductor type A-002-01-04 What type of semiconductor material contains more free electrons than pure germanium or silicon crystals? P-type Bipolar Superconductor A-002-01-05 What are the majority charge carriers in P-type semiconductor material? Free protrons Holes Free neutrons A-002-01-06 What are the majority charge carriers in N-type semiconductor material? Free protrons Free neutrons Free electrons A-002-01-07 Silicon, in its pure form, is: an insulator a semiconductor conductor A-002-01-08 An element which is sometimes an insulator and sometimes a conductor is called a: N-type conductor P-type conductor semiconductor A-002-01-09 Which of the following materials is used to make a semiconductor? copper silicon sulphur A-002-01-10 Substances such as silicon in a pure state are usually good: tuned circuits inductors insulators A-002-01-11 A semiconductor is said to be doped when it has added to it small quantities of: ions electrons impurities A-002-02-01 What is the principal characteristic of a zener diode? A negative resistance region An internal capacitance that varies with the applied voltage A constant voltage under conditions of varying current A-002-02-02 What type of semiconductor diode varies its internal capacitance as the voltage applied to its terminals varies? Zener Silicon-controlled rectifier Hot-carrier A-002-02-03 What is a common use for the hot-carrier diode? As balanced mixers in FM generation As a variable capacitance in an automatic frequency control circuit As a constant voltage reference in a power supply A-002-02-04 What limits the maximum forward current in a junction diode? Junction temperature Back EMF Peak inverse voltage A-002-02-05 What are the major ratings for junction diodes? Maximum forward current and capacitance Maximum forward current and PIV Maximum reverse current and PIV A-002-02-06 Structurally, what are the two main categories of semiconductor diodes? Electrolytic and point contact Junction and point contact Electrolytic and junction A-002-02-07 What is a common use for point contact diodes? As a constant voltage source As an RF detector As a high voltage rectifier A-002-02-08 What is one common use for PIN diodes? As an RF switch As a high voltage rectifier As a constant voltage source A-002-02-09 A Zener diode is a device used to: dissipate voltage decrease current increase current A-002-02-10 If a Zener diode rated at 10 V and 50 watts were operated at maximum dissipation rating, it would conduct ____ amperes: 0.05 5 0.5 A-002-02-11 The power-handling capability of most Zener diodes is rated at 25 degrees C or approximately room temperature. If the temperature is increased, the power handling capability is: less much greater slightly greater A-002-03-01 What is the alpha of a bipolar transistor? The change of collector current with respect to emitter current The change of base current with respect to collector current The change of collector current with respect to gate current A-002-03-02 What is the beta of a bipolar transistor? The change of collector current with respect to emitter current The change of base current with respect to gate current The change of collector current with respect to base current A-002-03-03 Which component conducts electricity from a negative emitter to a positive collector when its base voltage is made positive? A triode vacuum tube An NPN transistor A PNP transistor A-002-03-04 What is the alpha of a bipolar transistor in common base configuration? Reverse current gain Reverse voltage gain Forward current gain A-002-03-05 In a bipolar transistor, the change of collector current with respect to base current is called: beta delta alpha A-002-03-06 The alpha of a bipolar transistor is specified for what configuration? Common base Common gate Common emitter A-002-03-07 The beta of a bipolar transistor is specified for what configurations? Common base or common collector Common emitter or common collector Common base or common emitter A-002-03-08 Which component conducts electricity from a positive emitter to a negative collector when its base is made negative? A PNP transistor A varactor An NPN transistor A-002-03-09 Alpha of a bipolar transistor is equal to : beta / (1 + beta) beta X (1 - beta) beta / (1 - beta) A-002-03-10 The current gain of a bipolar transistor in common emitter or common collector compared to common base configuration is: very small usually about double usually about half A-002-03-11 Beta of a bipolar transistor is equal to: alpha / (1 + alpha) alpha X (1 - alpha) alpha X (1 + alpha) A-002-04-01 What is an enhancement-mode FET? An FET with a channel that blocks voltage through the gate An FET with a channel that allows current when the gate voltage is zero An FET without a channel to hinder current through the gate A-002-04-02 What is a depletion-mode FET? An FET that has a channel with no gate voltage applied; a current flows with zero gate voltage An FET without a channel to hinder current through the gate An FET that has a channel that blocks current when the gate voltage is zero A-002-04-03 Why do many MOSFET devices have built-in gate protective Zener diodes? The gate-protective Zener diode protects the substrate from excessive voltages The gate-protective Zener diode prevents the gate insulation from being punctured by small static charges or excessive voltages The gate-protective Zener diode provides a voltage reference to provide the correct amount of reverse-bias gate voltage A-002-04-04 Why are special precautions necessary in handling FET and CMOS devices? They are susceptible to damage from static charges They have micro-welded semiconductor junctions that are susceptible to breakage They have fragile leads that may break off A-002-04-05 How does the input impedance of a field-effect transistor (FET) compare with that of a bipolar transistor? An FET has low input impedance; a bipolar transistor has high input impedance The input impedance of FETs and bipolar transistors is the same An FET has high input impedance; a bipolar transistor has low input impedance A-002-04-06 What are the three terminals of a junction field-effect transistor (JFET)? Emitter, base, collector Gate, drain, source Gate 1, gate 2, drain A-002-04-07 What are the two basic types of junction field-effect transistors (JFET)? High power and low power MOSFET and GaAsFET Silicon and germanium A-002-04-08 Electron conduction in an n- channel depletion type MOSFET is associated with: p-channel depletion p-channel enhancement q-channel enhancement A-002-04-09 Electron conduction in an n- channel enhancement MOSFET is associated with: p-channel enhancement n-channel enhancement p-channel depletion A-002-04-10 Hole conduction in a p-channel depletion type MOSFET is associated with: p-channel depletion q-channel depletion n-channel depletion A-002-04-11 Hole conduction in a p-channel enhancement type MOSFET is associated with: n-channel enhancement q-channel enhancement p-channel enhancement A-002-05-01 What are the three terminals of a silicon controlled rectifier (SCR)? Base, collector and emitter Anode, cathode and gate Gate, source and sink A-002-05-02 What are the two stable operating conditions of a silicon controlled rectifier (SCR)? Conducting and non- conducting NPN conduction and PNP conduction Oscillating and quiescent A-002-05-03 When a silicon controlled rectifier (SCR) is triggered, to what other semiconductor diode are its electrical characteristics similar (as measured between its cathode and anode)? The PIN diode The hot-carrier diode The varactor diode A-002-05-04 Under what operating condition does a silicon controlled rectifier (SCR) exhibit electrical characteristics similar to a forward-biased silicon rectifier? When it is used as a detector During a switching transition When it is gated "on" A-002-05-05 The silicon controlled rectifier (SCR) is what type of device? NPPN PNNP PPNN A-002-05-06 The control element in the silicon controlled rectifier (SCR) is called the: cathode emitter gate A-002-05-07 The silicon controlled rectifier (SCR) is a member of which family? Varactors Thyristors Varistors A-002-05-08 In amateur radio equipment, which is the major application for the silicon controlled rectifier (SCR)? Class C amplifier circuit Microphone preamplifier circuit SWR detector circuit A-002-05-09 Which of the following devices has anode, cathode, and gate? The silicon controlled rectifier (SCR) The field effect transistor The triode vacuum tube A-002-05-10 When it is gated "on", the silicon controlled rectifier (SCR) exhibits electrical characteristics similar to a: forward-biased PIN diode reverse-biased hot-carrier diode forward-biased silicon rectifier A-002-05-11 Which of the following is a PNPN device? Hot carrier diode Zener diode Silicon controlled rectifier (SCR) A-002-06-01 For what portion of a signal cycle does a Class A amplifier operate? More than 180 degrees but less than 360 degrees The entire cycle Less than 180 degrees A-002-06-02 Which class of amplifier has the highest linearity and least distortion? Class AB Class B Class C A-002-06-03 For what portion of a cycle does a Class AB amplifier operate? The entire cycle Less than 180 degrees More than 180 degrees but less than 360 degrees A-002-06-04 For what portion of a cycle does a Class B amplifier operate? More than 180 degrees but less than 360 degrees 180 degrees The entire cycle A-002-06-05 For what portion of a signal cycle does a Class C amplifier operate? Less than 180 degrees The entire cycle 180 degrees A-002-06-06 Which class of amplifier provides the highest efficiency? Class A Class AB Class B A-002-06-07 In order to provide the greatest efficiency in the output stage of a CW, RTTY or FM transmitter, you would operate the amplifier: Class AB Class B Class A A-002-06-08 Which class of amplifier provides the least efficiency? Class B Class A Class AB A-002-06-09 Which class of amplifier has the poorest linearity and the most distortion? Class C Class A Class B A-002-06-10 Which class of amplifier operates over the full cycle? Class AB Class B Class C A-002-06-11 Which class of amplifier operates over less than 180 degrees of the cycle? Class C Class A Class B A-002-07-01 What determines the input impedance of a FET common- source amplifier? The input impedance is essentially determined by the resistance between the source and the drain The input impedance is essentially determined by the gate biasing network The input impedance is essentially determined by the resistance between the drain and substrate A-002-07-02 What determines the output impedance of a FET common- source amplifier? The output impedance is essentially determined by the drain resistor The output impedance is essentially determined by the gate supply voltage The output impedance is essentially determined by the input impedance of the FET A-002-07-03 What are the advantages of a Darlington pair audio amplifier? Mutual gain, high stability and low mutual inductance Mutual gain, low input impedance and low output impedance Low output impedance, high mutual impedance and low output current A-002-07-04 In the common base amplifier, when the input and output signals are compared : the signals are in phase the output signals leads the input signal by 90 degrees the signals are 180 degrees out of phase A-002-07-05 In the common base amplifier, the input impedance, when compared to the output impedance is: only slightly lower very low very high A-002-07-06 In the common emitter amplifier, when the input and output signals are compared: the output signal lags the input signal by 90 degrees the signals are 180 degrees out of phase the signals are in phase A-002-07-07 In the common collector amplifier, when the input and output signals are compared: the output signal lags the input signal by 90 degrees the signals are in phase the signals are 180 degrees out of phase A-002-07-08 The FET amplifier source follower circuit is another name for: common drain circuit common mode circuit common gate circuit A-002-07-09 The FET amplifier common source circuit is similar to which of the following bipolar transistor amplifier circuits? Common base Common mode Common emitter A-002-07-10 The FET amplifier common drain circuit is similar to which of the following bipolar transistor amplifier circuits? Common emitter Common base Common mode A-002-07-11 The FET amplifier common gate circuit is similar to which of the following bipolar transistor amplifier circuits? Common collector Common base Common emitter A-002-08-01 What is an operational amplifier (opamp)? An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit A program subroutine that calculates the gain of an RF amplifier A high-gain, direct-coupled differential amplifier whose characteristics are determined by components mounted externally A-002-08-02 What would be the characteristics of the ideal op-amp? impedance, infinite gain, and flat frequency response Infinite input impedance, zero output impedance, infinite gain, and flat frequency response Infinite input impedance, infinite output impedance, infinite gain and flat frequency response Zero input impedance, infinite output impedance, infinite gain, and flat frequency response A-002-08-03 What determines the gain of a closedloop op-amp circuit? The power supply voltage The external feedback network The collector-to-base capacitance of the PNP stage A-002-08-04 What is meant by the term op-amp offset voltage? The potential between the amplifier input terminals of the op-amp in a closed-loop condition The potential between the amplifier input terminals of the op-amp in an open-loop condition The output voltage of the op-amp minus its input voltage A-002-08-05 What is the input impedance of a theoretically ideal op-amp? Exactly 100 ohms Exactly 1000 ohms Very high A-002-08-06 What is the output impedance of a theoretically ideal op-amp? Exactly 100 ohms Exactly 1000 ohms Very low A-002-08-07 What are the advantages of using an opamp instead of LC elements in an audio filter? Op-amps are available in more styles and types than are LC elements Op-amps are fixed at one frequency Op-amps exhibit gain rather than insertion loss A-002-08-08 What are the principal uses of an op-amp RC active filter in amateur circuitry? Op-amp circuits are used as audio filters for receivers Op-amp circuits are used as filters for smoothing power supply output Op-amp circuits are used as high-pass filters to block RFI at the input of receivers A-002-08-09 What is an inverting op-amp circuit? An operational amplifier circuit connected such that the input and output signals are in phase An operational amplifier circuit connected such that the input and output signals are 90 degrees out of phase An operational amplifier circuit connected such that the input impedance is held to zero, while the output impedance is high A-002-08-10 What is a non-inverting op-amp circuit? An operational amplifier circuit connected such that the input and output signals are in phase An operational amplifier circuit connected such that the input impedance is held low, and the output impedance is high An operational amplifier circuit connected such that the input and output signals are 180 degrees out of phase A-002-08-11 What term is most appropriate for a high gain, direct-coupled differential amplifier whose characteristics are determined by components mounted externally? Operational amplifier High gain audio amplifier Summing amplifier A-002-09-01 What is the mixing process? The recovery of intelligence from a modulated signal The combination of two signals to produce sum and difference frequencies The elimination of noise in a wideband receiver by phase comparison A-002-09-02 What are the principal frequencies that appear at the output of a mixer circuit? 1.414 and 0.707 times the input frequencies The sum, difference and square root of the input frequencies Two and four times the original frequency A-002-09-03 What occurs when an excessive amount of signal energy reaches the mixer circuit? Spurious signals are generated A beat frequency is generated Mixer blanking occurs A-002-09-04 In a frequency multiplier circuit, the input signal is coupled to the base of a transistor through a capacitor. A radio frequency choke is connected between the base of the transistor and ground. The capacitor is: part of the input tuned circuit a by-pass for the circuit part of the output tank circuit A-002-09-05 A frequency multiplier circuit must be operated in: class B class A class C A-002-09-06 In a frequency multiplier circuit, an inductance (L1) and a variable capacitor (C2) are connected in series between VCC+ and ground. The collector of a transistor is connected to a tap on L1. The purpose of the variable capacitor is to: tune L1 to the frequency applied to the base provide positive feedback A-002-09-07 In a frequency multiplier circuit, an inductance (L1) and a variable capacitor (C2) are connected in series between VCC+ and ground. The collector of a transistor is connected to a tap on L1. A fixed capacitor (C3) is connected between the VCC+ side of L1 and ground. The purpose of C3 is to: resonate with L1 keep RF out of the power supply by-pass any audio components A-002-09-08 In a frequency multiplier circuit, an inductance (L1) and a variable capacitor (C2) are connected in series between VCC+ and ground. The collector of a transistor is connected to a tap on L1. C2 in conjunction with L1 operate as a: frequency multiplier voltage divider voltage doubler A-002-09-09 In a circuit where the components are tuned to resonate at a higher frequency than applied, the circuit is most likely a: a VHF/UHF amplifier a linear amplifier a frequency divider A-002-09-10 In a frequency multiplier circuit, an inductance (L1) and a variable capacitor (C2) are connected in series between VCC+ and ground. The collector of a transistor is connected to a tap on L1. A fixed capacitor (C3) is connected between the VCC+ side of L1 and ground. C3 is a: tuning capacitor RF by-pass capacitor coupling capacitor A-002-09-11 What stage in a transmitter would change a 5.3-MHz input signal to 14.3 MHz? A frequency multiplier A mixer A beat frequency oscillator A-002-10-01 What is a NAND gate? A circuit that produces a logic "0" at its output only when all inputs are logic "1" A circuit that produces a logic "0" at its output if some but not all of its inputs are logic "1" A circuit that produces a logic "0" at its output only when all inputs are logic "0" A-002-10-02 What is an OR gate? A circuit that produces a logic "1" at its output if any input is logic "1" A circuit that produces logic "1" at its output if all inputs are logic "0" A circuit that produces a logic "0" at its output if any input is logic "1" A-002-10-03 What is a NOR gate? A circuit that produces a logic "1" at its output only if all inputs are logic "1" A circuit that produces a logic "1" at its output if some but not all of its inputs are logic "1" A circuit that produces a logic "0" at its output if any or all inputs are logic "1" A-002-10-04 What is an INVERT gate? A circuit that allows data transmission only when its input is high A circuit that produces a logic "1" at its output when the input is logic "1" A circuit that produces a logic "0" at its output when the input is logic "1" A-002-10-05 What is an EXCLUSIVE OR gate? A circuit that produces a logic "1" at its output when all of the inputs are logic "1" A circuit that produces a logic "1" at its output when all of the inputs are logic "0" A circuit that produces a logic "1" at its output when only one of the inputs is logic "1" A-002-10-06 What is an EXCLUSIVE NOR gate? A circuit that produces a logic "1" at its output when only one of the inputs is logic "0" A circuit that produces a logic "1" at its output when only one of the inputs are logic "1" A circuit that produces a logic "0" at its output when all of the inputs are logic "1" A-002-10-07 What is an AND gate? A circuit that produces a logic "1" at its output only if one of its inputs is logic "1" A circuit that produces a logic "1" at its output if all inputs are logic "0" A circuit that produces a logic "1" at its output only if all its inputs are logic "1" A-002-10-08 What is a flip-flop circuit? A binary sequential logic element with two stable states A binary sequential logic element with four stable states A binary sequential logic element with one stable state A-002-10-09 What is a bistable multivibrator? An OR gate An AND gate A clock A-002-10-10 What type of digital logic is also known as a latch? An OR gate A flip-flop An op-amp A-002-10-11 In a multivibrator circuit, when one transistor conducts, the other is: reverse-biased cut off forward-biased A-002-11-01 What is a crystal lattice filter? An audio filter made with four quartz crystals that resonate at 1 kHz intervals A filter with narrow bandwidth and steep skirts made using quartz crystals A power supply filter made with interlaced quartz crystals A-002-11-02 What factor determines the bandwidth and response shape of a crystal lattice filter? The centre frequency chosen for the filter The gain of the RF stage following the filter The amplitude of the signals passing through the filter A-002-11-03 For single-sideband phone emissions, what would be the bandwidth of a good crystal lattice filter? 500 Hz 2.1 kHz 6 kHz A-002-11-04 The main advantage of a crystal oscillator over a tuned LC oscillator is: freedom from harmonic emissions simplicity much greater frequency stability A-002-11-05 A quartz crystal filter is superior to an LC filter for narrow bandpass applications because of the: LC circuit's high Q crystal's simplicity crystal's high Q A-002-11-06 Piezoelectricity is generated by: adding impurities to a crystal deforming certain crystals moving a magnet near a crystal A-002-11-07 Electrically, what does a crystal look like? A very low Q tuned circuit A variable capacitance A variable tuned circuit A-002-11-08 Crystals are sometimes used in a circuit which has an output an integral multiple of the crystal frequency. This circuit is called: a crystal lattice a crystal ladder an overtone oscillator A-002-11-09 Which of the following properties DOES NOT apply to a crystal when used in an oscillator circuit? Good frequency stability Very low noise because of high Q Good frequency accuracy A-002-11-10 Crystal oscillators, filters and microphones depend upon which principle? Hertzberg effect Ferro-resonance Overtone effect A-002-11-11 Crystals are NOT applicable to which of the following? Microphones Lattice filters Oscillators A-002-12-01 What are the three general groupings of filters? Audio, radio and capacitive High-pass, low-pass and band-pass Inductive, capacitive and resistive A-002-12-02 What are the distinguishing features of a Butterworth filter? It only requires conductors It has a maximally flat response over its pass-band It only requires capacitors A-002-12-03 Which filter type is decribed as having ripple in the passband and a sharp cutoff? A passive op-amp filter A Chebyshev filter A Butterworth filter A-002-12-04 What are the distinguishing features of a Chebyshev filter? It allows ripple in the passband in return for steeper skirts It requires only capacitors It has a maximally flat response in the passband A-002-12-05 Resonant cavities are used by amateurs as a: low pass-filter below 30 MHz narrow bandpass filter at VHF and higher frequencies high pass-filter above 30 MHz A-002-12-06 On VHF and above, 1/4 wavelength coaxial cavities are used to give protection from high-level signals. For a frequency of approximatively 50 MHz, the diameter of such a device would be about four inches (10 cm). What would be its approximate length? 0.6 metres (2 ft) 2.4 metres (8 ft) 3.7 metres (12 ft) A-002-12-07 A device which helps with receiver overload and spurious responses at VHF, UHF and above may be installed in the receiver front end. It is called a: diplexer directional coupler duplexer A-002-12-08 Where you require bandwidth at VHF and higher frequencies about equal to a television channel, a good choice of filter is the: Butterworth Chebyshev None of the above A-002-12-09 What is the primary advantage of the Butterworth filter over the Chebyshev filter? It requires only inductors It requires only capacitors It has maximally flat response over its passband A-002-12-10 What is the primary advantage of the Chebyshev filter over the Butterworth filter? It requires only inductors It allows ripple in the passband in return for steeper skirts It has maximally flat response over the passband A-002-12-11 Which of the following filter types IS NOT suitable for use at audio and low radio frequencies? Chebyshev Cavity Butterworth |
ARRL Amateur Radio News |
