Electrical Engineering Expert Answers & Study Resources

26. A well-designed voltage-divider bias circuit is one in which the voltage divider appears A. stiff to the input resistance of the base. B. soft to the input resistance of the base. C. stiff to the output resistance of the collector. D. stiff to the input resistance of the emitter. 27. Using a firm voltage.

11. The common-base amplifier is also called a grounded-base amplifier. 12. The output voltage of a common-base amplifier is out of phase with its input. 13. One of the major differences between the CB amplifier and other amplifier configurations is its A. low input impedance. B. low output impedance. C. high input impedance. D. input and.

46. What would the voltage be across RL if C shorted? A.ac B.120 Vdc C.pulsating filtered dc D. zero 47. A device that keeps the current through it fixed when the voltage changes is aA. zener diode. B. current-regulator diode. C.silicon rectifier. D.tunnel diode. 48. A diode that is useful in frequency multiplier circuits is aA. snap diode. B.slope diode. C.photo.

26. Examples of optoelectronic devices do not include ________. A. LEDs B. FETs C.photodiodes D.optocouplers 27. Which of the following is not an advantage of a light-emitting diode (LED)? A.low voltage B.long life C.fast on-off switching D. cost 28. LEDs have breakdown voltages that typically range from A. 3 to 5 V. B.1 to 2 V. C.6 to 10 V. D.10 to 15 V. 29..

46. The voltage measured across the base-emitter junction of the silicon transistor shown in Figure 7-29 (a) is ________. A. 0.3 V B. 1.3 V C. 0.7 V D. 1.7 V 47. In order to determine the emitter current for the circuit shown in Figure 7-21, you must A. subtract 0.7 V from 15 V and.

11. Transistor saturation and cutoff regions are useful in digital and computer circuits referred to as switching circuits. 12. Small-signal transistors can dissipate less than 1 watt. 13. The power rating of a transistor can be increased by using a heat sink. 14. In a system of analysis called h parameters, hFE is.

36. The intent of emitter-feedback bias is to A. reduce the source voltage. B. swamp out the variations in current gain. C. swamp out the base current. D. increase current gain. 37. Collector-feedback bias is also called A. collector-follower bias. B. emitter-feedback bias. C. voltage-divider bias. D. self-bias. 38. Collector-feedback bias is more effective than emitter-feedback bias and is used.

46. A multistage amplifier can be created by cascading two or more filter circuits. 47. What is a multistage amplifier? A. a single stage amplifier B. a single stage attenuator C. two or more attenuators cascaded D. two or more amplifiers cascaded 48. If two or more amplifiers are connected to form a multistage amplifier A. gain.

2. A zener diode is sometimes called a voltage-regulator diode because it maintains a constant output voltage even though the current through it changes. 3. The zener diode must remain in the breakdown region under all operating conditions in order for a zener regulator to hold the output voltage constant. 4. The.

11. If RE is adjusted it its minimum value in Figure 7-16, the Q point moves toward cut-off. 12. With the values shown at the operating point labeled Q, the voltage across RC would be 10 V. 13. Some electronic equipment has a power supply that produces both positive and negative supply.

31. If the data sheet maximum rating, collector-emitter breakdown voltage is exceeded A. current gain becomes maximum. B. the emitter will become reverse biased. C. the transistor will go into cut-off. D. the transistor will breakdown and will probably be destroyed. 32. A transistor has a power dissipation that equals ________. A. VCE x RC B. VCE.

21. The type of biasing that produces the most useful results is A. forward-biasing the emitter diode and reverse-biasing the collector diode. B. reverse-biasing the emitter diode and forward-biasing the collector diode. C. forward-biasing the collector diode and reverse-biasing the base diode. D. reverse-biasing the collector diode and forward-biasing the base diode. 22. The base.

16. Collector-feedback bias is also called A. self-bias. B. collector follower. C. negative collector. D. voltage-divider. 17. Collector-feedback bias is still sensitive to changes in current gain, but it is used because of its A. small size. B. low cost. C. simplicity. D. complexity. 18. Emitter-feedback and collector-feedback are typically not adequate because A. there is too much negative feedback. B. there.

16. With a common-collector amplifier, the input signal is A. coupled to the base and the output signal is taken from the emitter. B. coupled to the base and the output signal is taken from the collector. C. coupled to the emitter and the output signal is taken from the collector. D. coupled to.

A. an ac open. B. a dc short. C. a dc open. D. an ac short. 22. The reactance of a coupling capacitor at dc voltage is ________. A. zero B. infinite C. 100 kW D. 1.414 W 23. The base current for the circuit shown in Figure 8-2 (a) can be determined by A. dividing 100 by 5 kW. B..

2. In a common-collector amplifier, the emitter is always connected to ground. 3. One of the advantages of an emitter follower is its high output impedance. 4. It is very difficult to get a small output impedance with a common-collector amplifier. 5. An emitter follower can act as a buffer between the high.

21. In order to maintain a constant output voltage, the zener diode A. must be connected to a transformer. B. must remain forward biased. C. must remain in the breakdown region. D. must be in series with a filter capacitor 22. Zener diodes are available with power ratings that range from A. ½ to more than.

26. What type transistor connection is shown in Figure 6-7 (a)? A. common emitter B. common collector C. common base D. emitter follower 27. What is the source of bias for the transistor's emitter diode shown in Figure 6-7 (a)? A. VCC B. VBB C. VCE D. RC 28. What is the purpose of RB in the circuit shown in.

6. The dc beta is defined as the dc collector current divided by the dc emitter current. 7. The dc beta is also known as the current gain because a small base current controls a much larger collector current. 8. When the ground side of each voltage source is connected to the.

A. C3 open B. C3 shorted C. C2 open D. C2 shorted 47. In the circuit shown in Figure 8-30, if the collector voltage is 0 V and the base voltage is 0 V, what is the trouble? A. 1 mV generator open B. C1 open C. C3 shorted D. +10 V supply is faulty 48.In the circuit shown.

31. The biasing configuration shown in Figure 7-18 is derived from emitter bias and is referred to as A. emitter derived bias (EDB). B. bi-polar emitter bias (BPEB). C. two-supply emitter bias (TSEB). D. one-supply emitter bias (OSEB). 32. By exposing a transistor's collector junction to light, a manufacturer can produce A. an LED. B. a seven-segment.

36.What kind of diode has a metal such as gold or silver on one side of the junction and doped silicon on the other side? A.tunnel B.small-signal C. Schottky D. Zener 37. The Schottky diode has A. a large depletion layer. B. no depletion layer. C.a high reverse recovery time. D.no junction. 38. The Schottky diode is sometimes called a A.silicon.

6. The zener diode data sheet rating, maximum current is the highest amount of current a zener diode can handle without exceeding its power rating. 7. A shorted component is equivalent to a resistance of zero, and an open component is equivalent to a resistance of infinity. 8.Optoelectronics is the technology that.

31. The combination of an LED and a photodiode is called a(n) A.seven-segment display. B.laser. C.LCD. D. optocoupler. 32.What type of cable is comprised of thin flexible fibers of glass or plastic that transmit light beams instead of free electrons? A.coaxial B.stranded copper cable C. fiber-optic D. wave guide 33. What type of instrument can be used to test for.

16. The zener diode is the backbone of A. constant current sources. B. passive filters. C. voltage regulators. D. oscillator circuits. 17. What type of bias is required for normal operation of a zener diode? A. reverse B. forward C. positive D. negative 18. What is the circuit shown in Figure 5-2 (a)? A. RZ filter B. zener regulator C. voltage doubler D. half-wave.

6. A Darlington connection is a connection of two transistors whose overall current gain equals the sum of the individual gains. 7. A complementary Darlington is a connection of npn and pnp transistors. 8. Used with a zener diode, an emitter follower can produce regulated output voltages with much larger currents. 9. A.

41. In most applications, a small-signal transistor is not fan-cooled A. but it does have a heat sink. B. and it does not have a heat sink. C. but it can be used as a power transistor. D. and case temperatures are usually above 30°C. 42. The only way to keep a transistor case temperature.

41. With ambiguous troubles, the troubleshooter very often must A. replace all suspected components. B. memorize the circuit diagram. C. disconnect one suspected component and test it. D. disconnect all suspected components and apply power. 42. What should a troubleshooter do if the base, collector, and emitter voltages in a transistor circuit all measure 0.

A. ac resistance. B. dc resistance. C. reactance. D. impedance. 37. An equivalent transistor circuit model used to analyze ac signal processing that looks like a T on its side is the A. Fourier model. B. p model. C. Thevenin model. D. Ebers-Moll model. 38. What is the most popular circuit model that is used to analyze how a.

46. When working with h parameter analysis, the symbol for current gain is ________. A. bDC B. hFE C. aFED. D. D 47. What type of transistor is usually found in a simple three-terminal, gull-wing package? A. chassis mount B. printed-circuit C. surface-mount D. power 48. What is the surface-mount package called that resembles the dual-inline package and houses multiple.

6. A bypass capacitor is similar to a coupling capacitor because it appears open to dc and shorted to ac. 7.Voltage gain is ac output voltage divided by the ac input voltage. 8. Discrete means all components like resistors, capacitors, and transistors are created and connected on a chip, a piece of.

A. power output. B. power gain. C. voltage gain. D. beta. 27. When a single or double stage amplifier is not working, troubleshooting can begin by measuring dc voltages. 28. In order for a bypass capacitor to work properly, its reactance must be A. much smaller than the resistance. B. much larger than the resistance. C. equal to.

2. In an npn transistor, the emitter and collector are both n-type materials. 3. The emitter of a bipolar junction transistor is lightly doped and the base is heavily doped. 4.An unbiased transistor is like two back-to-back diodes. 5. The emitter current in a bipolar junction transistor is equal to the sum of.

A. oscillation B. amplification C. distortion D. extortion 32. Distortion is undesirable in high-fidelity amplifiers because A. it changes the sound of voice and music. B. it amplifies the sound of voice and music. C. it trips a circuit breaker. D. it cannot be heard in either speaker. 33. What is one way to minimize distortion? A. use batteries only B..

36. Transistor saturation and cutoff regions are used in circuits referred to as ________. A. rectifiers B. filters C. switching circuits D. amplifiers 37. In a common-emitter circuit, once the base current has been calculated, collector current can be determined by multiplying base current by ________. A. alpha B. the load resistor C. maximum power rating D. beta 38. When.

2.Voltage-divider bias is really emitter bias in disguise. 3. In the circuit shown in Figure 7-12, the first step in finding the emitter current is to determine the voltage across R2. 4. The emitter-base junction voltage of the silicon transistor shown in Figure 7-12 is approximated to be 0.3 V. 5. The emitter.

21. In any amplifier, maximum power transfer occurs when the A. load impedance is much higher than the source impedance. B. load impedance is much lower than the source impedance. C. load impedance is made equal to the source impedance. D. load impedance is infinite and source impedance is zero. 22. When an emitter follower.

2. A coupling capacitor couples an ac signal into an amplifier without disturbing its operating point. 3.Coupling capacitors can be approximated as dc shorts. 4.If there is any ac voltage at an amplifier's bypass emitter, it means that the A. transistor is shorted. B. transistor is open. C. coupling capacitor is open. D. bypass capacitor is.

12. It is standard practice to use capital letters and subscripts for dc quantities. 13. The ac resistance of the emitter diode equals the ac base-emitter voltage divided by the ac emitter current. 14. The ac equivalent circuit model called the Ebers-Moll looks like a P on its side and is sometimes.

16. The middle region of a transistor is the ________. A. collector B. emitter C. base D. beta 17. Which region of the transistor is physically the largest? A. collector B. emitter C. base D. beta 18. The two junctions of a transistor are between the emitter and the base and between the A. collector and emitter. B. collector and base. C. collector.

26. Semiconductor manufacturers make Darlington pairs inside a single case. What is this device known as? A. Semiconductor single case B. Darlington transistor C. power transistor D. regulator transistor 27. A Darlington connection comprised of npn and pnp transistors is called a A. stationary Darlington. B. Duo-Darlington. C. supplementary Darlington. D. complementary Darlington. 28. In conjunction with a zener diode,.

41. With a varactor diode, the more it is reversed bias, its capacitance A. decreases. B.increases. C.remains the same. D.increases to 27 µF. 42. A varactor is often connected in parallel with an inductor to form a A.bridge rectifier. B.tunnel oscillator. C. parallel resonant circuit. D. parallelogram. 43. The capacitance exhibited by a varactor diode is controlled by ________. A. voltage B.current C.parallel.

41. It is very difficult to get a small output impedance with a A. common-collector amplifier. B. common-emitter amplifier. C. common-base amplifier. D. emitter-follower amplifier. 42. What is the circuit shown in Figure 9-16 (c)? A. two cascaded common-emitter amplifiers B. a small-signal amplifier C. a supplementary Darlington D. a complementary Darlington 43. What is the circuit shown in Figure.

36. The reason a common-collector amplifier is called an emitter follower is because A. the output voltage follows the input voltage. B. the output voltage is taken from the collector. C. the emitter is grounded. D. the output voltage is out of phase with the input. 37. What is the base voltage for the circuit.

31. The zener follower provides the regulation of a zener diode with the increased current-handling capability of a A. common-collector circuit. B. common-emitter circuit. C. common-base circuit. D. common-follower circuit. 32. The amplifier configuration in which the input signal drives the emitter and the output signal is taken from the collector is the A. common collector. B..

17. What is the mathematical approach that models the transistor on what is happening at its terminals without regard for the physical processes taking place inside the transistor? A. small-signal characteristics B. Thevenin's Theorem C. Kirchoff's Laws D. h parameters 18. One way to stabilize voltage gain is to leave some of the emitter resistance.

11. The Schottky diode has metal on one side of the junction and therefore has no depletion layer. 12. A varactor is a variable voltage multiplier. 13. A varistor is a semiconductor device that operates like two back-to-back zener diodes with a high breakdown in both directions. 14. Step-recovery diodes are useful in.

6. A well-designed voltage-divider bias circuit is one in which the voltage divider appears stiff to the input resistance of the base. 7.With the switch in the position as shown in Figure 7-4 (a), the LED is on. 8. A firm voltage divider means that the collector current will be approximately 10.

21. While troubleshooting the circuit shown in Figure 7-26, the base voltage measures 1.8 V and the collector voltage measures 10 V, what should the technician do? A. replace the transistor B. replace RE C. check R1 D. check voltage source and leads 22. What type transistor is used when the electronics equipment has a.

42. Amplified ripple out of a loudspeaker is detected as A. sine waves. B. high pitch noise. C. high frequency signals. D. low frequency hum. 43. In the circuit shown in Figure 8-4, what effect do the capacitors have on the dc biasing? A. add 0.7 V B. add 15 V C. puts transistor in cutoff D. no effect 44..