E6 Circuit Components Flashcards
E6A01 (C) In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?
C. In microwave circuits
E6A02 (A) Which of the following semiconductor materials contains excess free electrons?
A. N-type
E6A03 (C) Why does a PN-junction diode not conduct current when reverse biased?
C. Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
E6A04 (C) What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?
C. Acceptor impurity
E6A05 (C) What is the alpha of a bipolar junction transistor?
C. The change of collector current with respect to emitter current
E6A06 (B) What is the beta of a bipolar junction transistor?
B. The change in collector current with respect to base current
E6A07 (D) Which of the following indicates that a silicon NPN junction transistor is biased on?
D. Base-to-emitter voltage of approximately 0.6 to 0.7 volts
E6A08 (D) What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?
D. Alpha cutoff frequency
E6A09 (A) What is a depletion-mode FET?
A. An FET that exhibits a current flow between source and drain when no gate voltage is applied
E6A10 (B) In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

B. 4
E6A11 (A) In Figure E6-2, what is the schematic symbol for a P-channel junction FET?

A. 1
E6A12 (D) Why do many MOSFET devices have internally connected Zener diodes on the gates?
D. To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages
E6A13 (C) What do the initials CMOS stand for?
C. Complementary Metal-Oxide Semiconductor
E6A14 (C) How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?
C. An FET has high input impedance; a bipolar transistor has low input impedance
E6A15 (B) Which semiconductor material contains excess holes in the outer shell of electrons?
B. P-type
E6A16 (B) What are the majority charge carriers in N-type semiconductor material?
B. Free electrons
E6A17 (D) What are the names of the three terminals of a field-effect transistor?
D. Gate, drain, source
E6B01 (B) What is the most useful characteristic of a Zener diode?
B. A constant voltage drop under conditions of varying current
E6B02 (D) What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?
D. Less forward voltage drop
E6B03 (C) What special type of diode is capable of both amplification and oscillation?
C. Tunnel
E6B04 (A) What type of semiconductor device is designed for use as a voltage-controlled capacitor?
A. Varactor diode
E6B05 (D) What characteristic of a PIN diode makes it useful as an RF switch or attenuator?
D. A large region of intrinsic material
E6B06 (D) Which of the following is a common use of a hot-carrier diode?
D. As a VHF/UHF mixer or detector
E6B07 (B) What is the failure mechanism when a junction diode fails due to excessive current?
B. Excessive junction temperature
E6B08 (A) Which of the following describes a type of semiconductor diode?
A. Metal-semiconductor junction
E6B09 (C) What is a common use for point contact diodes?
C. As an RF detector
E6B10 (B) In Figure E6-3, what is the schematic symbol for a light-emitting diode?

B. 5
E6B11 (A) What is used to control the attenuation of RF signals by a PIN diode?
A. Forward DC bias current
E6B12 (C) What is one common use for PIN diodes?
C. As an RF switch
E6B13 (B) What type of bias is required for an LED to emit light?
B. Forward bias
E6C01 (A) What is the function of hysteresis in a comparator?
A. To prevent input noise from causing unstable output signals
E6C02 (B) What happens when the level of a comparator’s input signal crosses the threshold?
B. The comparator changes its output state
E6C03 (A) What is tri-state logic?
A. Logic devices with 0, 1, and high impedance output states
E6C04 (B) What is the primary advantage of tri-state logic?
B. Ability to connect many device outputs to a common bus
E6C05 (D) What is an advantage of CMOS logic devices over TTL devices?
D. Lower power consumption
E6C06 (C) Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?
C. The input switching threshold is about one-half the power supply voltage
E6C07 (B) What best describes a pull-up or pull-down resistor?
B. A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
E6C08 (B) In Figure E6-5, what is the schematic symbol for a NAND gate?

B. 2
E6C09 (B) What is a Programmable Logic Device (PLD)?
B. A programmable collection of logic gates and circuits in a single integrated circuit
E6C10 (D) In Figure E6-5, what is the schematic symbol for a NOR gate?

D. 4
E6C11 (C) In Figure E6-5, what is the schematic symbol for the NOT operation (inverter)?

C. 5
E6C12 (D) What is BiCMOS logic?
D. An integrated circuit logic family using both bipolar and CMOS transistors
E6C13 (C) Which of the following is an advantage of BiCMOS logic?
C. It has the high input impedance of CMOS and the low output impedance of bipolar transistors
E6C14 (B) What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?
B. Complex logic functions can be created in a single integrated circuit
E6D01 (A) How many turns will be required to produce a 5-microhenry inductor using a powdered-iron toroidal core that has an inductance index (A L) value of 40 microhenrys/100 turns?
A. 35 turns
E6D02 (A) What is the equivalent circuit of a quartz crystal?
A. Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
E6D03 (A) Which of the following is an aspect of the piezoelectric effect?
A. Mechanical deformation of material by the application of a voltage
E6D04 (B) Which materials are commonly used as a slug core in a variable inductor?
B. Ferrite and brass
E6D05 (C) What is one reason for using ferrite cores rather than powdered-iron in an inductor?
C. Ferrite toroids generally require fewer turns to produce a given inductance value
E6D06 (D) What core material property determines the inductance of a toroidal inductor?
D. Permeability
E6D07 (B) What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?
B. From less than 20 Hz to approximately 300 MHz
E6D08 (B) What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?
B. Powdered-iron cores generally maintain their characteristics at higher currents
E6D09 (C) What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?
C. Ferrite beads
E6D10 (A) What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?
A. Toroidal cores confine most of the magnetic field within the core material
E6D11 (C) How many turns will be required to produce a 1-mH inductor using a core that has an inductance index (A L) value of 523 millihenrys/1000 turns?
C. 43 turns
E6D12 (C) What is the definition of saturation in a ferrite core inductor?
C. The ability of the inductor’s core to store magnetic energy has been exceeded
E6D13 (A) What is the primary cause of inductor self-resonance?
A. Inter-turn capacitance
E6D14 (B) Which type of slug material decreases inductance when inserted into a coil?
B. Brass
E6D15 (A) What is current in the primary winding of a transformer called if no load is attached to the secondary?
A. Magnetizing current
E6D16 (D) What is the common name for a capacitor connected across a transformer secondary that is used to absorb transient voltage spikes?
D. Snubber capacitor
E6D17 (A) Why should core saturation of a conventional impedance matching transformer be avoided?
A. Harmonics and distortion could result
E6E01 (C) Which of the following is true of a charge-coupled device (CCD)?
C. It samples an analog signal and passes it in stages from the input to the output
E6E02 (A) Which of the following device packages is a through-hole type?
A. DIP
E6E03 (D) Which of the following materials is likely to provide the highest frequency o
D. Gallium nitride
E6E04 (A) Which is the most common input and output impedance of circuits that use MMICs?
A. 50 ohms
E6E05 (A) Which of the following noise figure values is typical of a low-noise UHF preamplifier?
A. 2 dB
E6E06 (D) What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?
D. Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
E6E07 (B) Which of the following is typically used to construct a MMIC-based microwave amplifier?
B. Microstrip construction
E6E08 (A) How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?
A. Through a resistor and/or RF choke connected to the amplifier output lead
E6E09 (D) Which of the following component package types would be most suitable for use at frequencies above the HF range?
D. Surface mount
E6E10 (D) What is the packaging technique in which leadless components are soldered directly to circuit boards?
D. Surface mount
E6E11 (D) What is a characteristic of DIP packaging used for integrated circuits?
D. A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
E6E12 (B) Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?
B. Better dissipation of heat
E6F01 (B) What is photoconductivity?
B. The increased conductivity of an illuminated semiconductor
E6F02 (A) What happens to the conductivity of a photoconductive material when light shines on it?
A. It increases
E6F03 (D) What is the most common configuration of an optoisolator or optocoupler?
D. An LED and a phototransistor
E6F04 (B) What is the photovoltaic effect?
B. The conversion of light to electrical energy
E6F05 (A) Which describes an optical shaft encoder?
A. A device which detects rotation of a control by interrupting a light source with a patterned wheel
E6F06 (A) Which of these materials is affected the most by photoconductivity?
A. A crystalline semiconductor
E6F07 (B) What is a solid state relay?
B. A device that uses semiconductors to implement the functions of an electromechanical relay
E6F08 (C) Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?
C. Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
E6F09 (D) What is the efficiency of a photovoltaic cell?
D. The relative fraction of light that is converted to current
E6F10 (B) What is the most common type of photovoltaic cell used for electrical power generation?
B. Silicon
E6F11 (B) What is the approximate open-circuit voltage produced by a fully-illuminated silicon photovoltaic cell?
B. 0.5 V
E6F12 (C) What absorbs the energy from light falling on a photovoltaic cell?
C. Electrons
E6F13 (B) What is a liquid crystal display (LCD)?
B. A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
E6F14 (B) Which of the following is true of LCD displays?
B. They may be hard view through polarized lenses