A-002 — Advanced components and circuits

Advanced components and circuits: semiconductors, amplifier classes, oscillators, mixers, filters and digital logic.

All 132 questions

• A-002-001-001 What two elements widely used in semiconductor devices exhibit both metallic and non-metallic characteristics?
• A-002-001-002 In what application is gallium-arsenide used as a semiconductor material in preference to germanium or silicon?
• A-002-001-003 What type of semiconductor material contains fewer free electrons than pure germanium or silicon crystals?
• A-002-001-004 What type of semiconductor material contains more free electrons than pure germanium or silicon crystals?
• A-002-001-005 What are the majority charge carriers in P-type semiconductor material?
• A-002-001-006 What are the majority charge carriers in N-type semiconductor material?
• A-002-001-007 Silicon, in its pure form, is:
• A-002-001-008 An element which is sometimes an insulator and sometimes a conductor is called a:
• A-002-001-009 Which of the following materials is used to make a semiconductor?
• A-002-001-010 Substances such as silicon in a pure state are usually good:
• A-002-001-011 A semiconductor is said to be doped when it has added to it small quantities of:
• A-002-002-001 What is the principal characteristic of a Zener diode?
• A-002-002-002 What type of semiconductor diode varies its internal capacitance as the voltage applied to its terminals varies?
• A-002-002-003 What is a common use for the hot-carrier (Schottky) diode?
• A-002-002-004 What limits the maximum forward current in a junction diode?
• A-002-002-005 What are the major ratings for junction diodes?
• A-002-002-006 Structurally, what are the two main categories of semiconductor diodes?
• A-002-002-007 What is a common use for point contact diodes?
• A-002-002-008 What is one common use for PIN diodes?
• A-002-002-009 A Zener diode is a device used to:
• A-002-002-010 If a Zener diode rated at 10 V and 50 watts was operated at maximum dissipation rating, it would conduct ____ amperes:
• A-002-002-011 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:
• A-002-003-001 What is the alpha of a bipolar transistor?
• A-002-003-002 What is the beta of a bipolar transistor?
• A-002-003-003 Which component conducts electricity from a negative emitter to a positive collector when its base voltage is made positive?
• A-002-003-004 What is the alpha of a bipolar transistor in common base configuration?
• A-002-003-005 In a bipolar transistor, the change of collector current with respect to base current is called:
• A-002-003-006 The alpha of a bipolar transistor is specified for what configuration?
• A-002-003-007 The beta of a bipolar transistor is specified for what configurations?
• A-002-003-008 Which component conducts electricity from a positive emitter to a negative collector when its base is made negative?
• A-002-003-009 Alpha of a bipolar transistor is equal to:
• A-002-003-010 The current gain of a bipolar transistor in common emitter or common collector compared to common base configuration is:
• A-002-003-011 Beta of a bipolar transistor is equal to:
• A-002-004-001 What is an enhancement-mode FET?
• A-002-004-002 What is a depletion-mode FET?
• A-002-004-003 Why do many MOSFET devices have built-in gate protective Zener diodes?
• A-002-004-004 Why are special precautions necessary in handling FET and CMOS devices?
• A-002-004-005 How does the input impedance of a field-effect transistor (FET) compare with that of a bipolar transistor?
• A-002-004-006 What are the three terminals of a junction field-effect transistor (JFET)?
• A-002-004-007 What are the two basic types of junction field-effect transistors (JFET)?
• A-002-004-008 Electron conduction in an n-channel depletion type MOSFET is associated with:
• A-002-004-009 Electron conduction in an n-channel enhancement MOSFET is associated with:
• A-002-004-010 Hole conduction in a p-channel depletion type MOSFET is associated with:
• A-002-004-011 Hole conduction in a p-channel enhancement type MOSFET is associated with:
• A-002-005-001 What are the three terminals of a silicon controlled rectifier (SCR)?
• A-002-005-002 What are the two stable operating conditions of a silicon controlled rectifier (SCR)?
• A-002-005-003 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)?
• A-002-005-004 Under what operating condition does a silicon controlled rectifier (SCR) exhibit electrical characteristics similar to a forward-biased silicon rectifier?
• A-002-005-005 The silicon controlled rectifier (SCR) is what type of device?
• A-002-005-006 The control element in the silicon controlled rectifier (SCR) is called the:
• A-002-005-007 The silicon controlled rectifier (SCR) is a member of which family?
• A-002-005-008 In amateur radio equipment, which is the major application for the silicon controlled rectifier (SCR)?
• A-002-005-009 Which of the following devices has anode, cathode, and gate?
• A-002-005-010 When it is gated "on", the silicon controlled rectifier (SCR) exhibits electrical characteristics similar to a:
• A-002-005-011 Which of the following is a PNPN device?
• A-002-006-001 For what portion of a signal cycle does a Class A amplifier operate?
• A-002-006-002 Which class of amplifier has the highest linearity and least distortion?
• A-002-006-003 For what portion of a cycle does a Class AB amplifier operate?
• A-002-006-004 For what portion of a cycle does a Class B amplifier operate?
• A-002-006-005 For what portion of a signal cycle does a Class C amplifier operate?
• A-002-006-006 Which of the following classes of amplifier provides the highest efficiency?
• A-002-006-007 Which of the following classes of amplifier would provide the highest efficiency in the output stage of a CW, RTTY or FM transmitter?
• A-002-006-008 Which class of amplifier provides the least efficiency?
• A-002-006-009 Which class of amplifier has the poorest linearity and the most distortion?
• A-002-006-010 Which class of amplifier operates over the full cycle?
• A-002-006-011 Which class of amplifier operates over less than 180 degrees of the cycle?
• A-002-007-001 What determines the input impedance of a FET common-source amplifier?
• A-002-007-002 What determines the output impedance of a FET common-source amplifier?
• A-002-007-003 What are the advantages of a Darlington pair audio amplifier?
• A-002-007-004 In the common base amplifier, when the input and output signals are compared:
• A-002-007-005 In the common base amplifier, the input impedance, when compared to the output impedance is:
• A-002-007-006 In the common emitter amplifier, when the input and output signals are compared:
• A-002-007-007 In the common collector amplifier, when the input and output signals are compared:
• A-002-007-008 The FET amplifier source follower circuit is another name for:
• A-002-007-009 The FET amplifier common source circuit is similar to which of the following bipolar transistor amplifier circuits?
• A-002-007-010 The FET amplifier common drain circuit is similar to which of the following bipolar transistor amplifier circuits?
• A-002-007-011 The FET amplifier common gate circuit is similar to which of the following bipolar transistor amplifier circuits?
• A-002-008-001 What is an operational amplifier (op-amp)?
• A-002-008-002 What would be the characteristics of the ideal op-amp?
• A-002-008-003 What determines the gain of a closed-loop op-amp circuit?
• A-002-008-004 What is meant by the term op-amp offset voltage?
• A-002-008-005 What is the input impedance of a theoretically ideal op-amp?
• A-002-008-006 What is the output impedance of a theoretically ideal op-amp?
• A-002-008-007 What are the advantages of using an op-amp instead of LC elements in an audio filter?
• A-002-008-008 What are the principal uses of an op-amp RC active filter in amateur circuitry?
• A-002-008-009 What is an inverting op-amp circuit?
• A-002-008-010 What is a non-inverting op-amp circuit?
• A-002-008-011 What term is most appropriate for a high gain, direct-coupled differential amplifier whose characteristics are determined by components mounted externally?
• A-002-009-001 What is the mixing process?
• A-002-009-002 What are the principal frequencies that appear at the output of a mixer circuit?
• A-002-009-003 What occurs when an excessive amount of signal energy reaches the mixer circuit?
• A-002-009-004 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:
• A-002-009-005 A frequency multiplier circuit must be operated in:
• A-002-009-006 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:
• A-002-009-007 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:
• A-002-009-008 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:
• A-002-009-009 In a circuit where the components are tuned to resonate at a higher frequency than applied, the circuit is most likely a:
• A-002-009-010 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:
• A-002-009-011 What stage in a transmitter would change a 5.3-MHz input signal to 14.3 MHz?
• A-002-010-001 What is a NAND gate?
• A-002-010-002 What is an OR gate?
• A-002-010-003 What is a NOR gate?
• A-002-010-004 What is a NOT gate (also known as an INVERTER)?
• A-002-010-005 What is an EXCLUSIVE OR gate?
• A-002-010-006 What is an EXCLUSIVE NOR gate?
• A-002-010-007 What is an AND gate?
• A-002-010-008 What is a flip-flop circuit?
• A-002-010-009 What is a bistable multivibrator?
• A-002-010-010 What type of digital logic is also known as a latch?
• A-002-010-011 In a multivibrator circuit, when one transistor conducts, the other is:
• A-002-011-001 What is a crystal lattice filter?
• A-002-011-002 What factor determines the bandwidth and response shape of a crystal lattice filter?
• A-002-011-003 For single-sideband phone emissions, what would be the bandwidth of a good crystal lattice filter?
• A-002-011-004 The main advantage of a crystal oscillator over a tuned LC oscillator is:
• A-002-011-005 A quartz crystal filter is superior to an LC filter for narrow bandpass applications because of the:
• A-002-011-006 Piezoelectricity is generated by:
• A-002-011-007 Electrically, what does a crystal look like?
• A-002-011-008 Crystals are sometimes used in a circuit which has an output close to an integral multiple of the crystal frequency. This circuit is called:
• A-002-011-009 Which of the following properties does not apply to a crystal when used in an oscillator circuit?
• A-002-011-010 Crystal oscillators, filters and microphones depend upon which principle?
• A-002-011-011 Crystals are not applicable to which of the following?
• A-002-012-001 What are the three general groupings of filters?
• A-002-012-002 What are the distinguishing features of a Butterworth filter?
• A-002-012-003 Which filter type is described as having ripple in the passband and a sharp cutoff?
• A-002-012-004 What are the distinguishing features of a Chebyshev filter?
• A-002-012-005 Resonant cavities are used by amateurs as a:
• A-002-012-006 On VHF and above, 1/4 wavelength coaxial cavities are used to give protection from high-level signals. For a frequency of approximately 50 MHz, the diameter of such a device would be about 10 cm (4 in). What would be its approximate length?
• A-002-012-007 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:
• A-002-012-008 Where you require bandwidth at VHF and higher frequencies about equal to a television channel, a good choice of filter is the:
• A-002-012-009 What is the primary advantage of the Butterworth filter over the Chebyshev filter?
• A-002-012-010 What is the primary advantage of the Chebyshev filter over the Butterworth filter?
• A-002-012-011 Which of the following filter types is not suitable for use at audio and low radio frequencies?