1) A silicon diode measures a low value of resistance with the meter leads in both positions. The trouble, if any, is

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2 1) A silicon diode measures a low value of resistance with the meter leads in both positions. The trouble, if any, is A [ ]) the diode is open. B [ ]) the diode is shorted to ground. C [v]) the diode is internally shorted. D [ ]) the diode is working correctly. 2) For a forward-biased diode, the barrier potential as temperature increases. A [v]) decreases B []) remains constant C []) increases D [v]) None of above 3) The wide end arrow on a schematic indicates the of a diode. A []) ground B []) direction of electron flow C []) cathode D [v]) anode 4) An n-type semiconductor material A []) is intrinsic. B []) has trivalent impurity atoms added. C [v]) has pentavalent impurity atoms added. D []) requires no doping. 5) For a forward-biased diode, as temperature is, the forward current for a given value of forward voltage. A [ ]) decreased, increases B [v]) increased, increases

3 C [ ]) increased, decreases D [ ]) decreased, decreases 6) Which statement best describes an insulator? A []) A material with many free electrons. B []) A material doped to have some free electrons. C [v]) A material with few free electrons. D []) none of these 7) An ideal diode presents a(n) when reversed-biased and a(n) when forward-biased. A [v]) open, short B [ ]) short, open C [ ]) open, open D [ ]) short, short 8) A reverse-biased diode has the connected to the positive side of the source, and the connected to the negative side of the source. A [v]) cathode, anode B [ ]) cathode, base C [ ]) base, anode D [ ]) anode, cathode 9) What types of impurity atoms are added to increase the number of conduction-band electrons in intrinsic silicon? A [ ]) bivalent B [v]) pentavalent C [ ]) trivalent D [ ]) none of these 10) What factor(s) do(es) the barrier potential of a pn junction depend on? A [ ]) type of semiconductive material B [ ]) the amount of doping

4 C [ ]) the temperature D [v]) all of the above 11) Reverse breakdown is a condition in which a diode A [v]) is subjected to a large reverse voltage B []) is reverse-biased and there is a small leakage current. C []) has no current flowing at all. D []) is heated up by large amounts of current in the forward direction. 12) There is a small amount of current across the barrier of a reverse-biased diode. This current is called A [ ]) forward-bias current. B [ ]) reverse breakdown current. C [ ]) conventional current. D [v]) reverse leakage current 13) As the forward current through a silicon diode increases, the voltage across the diode A []) increases to a 0.7 V maximum. B []) decreases. C [v]) is relatively constant. D []) decreases and then increases. 14) Doping of a semiconductor material means A []) Doping of a semiconductor material means B []) that impurities are added to increase the resistance of the material. C [v]) that impurities are added to decrease the resistance of the material D []) that all impurities are removed to get pure silicon. 15) The forward voltage across a conducting silicon diode is about A []) 0.3 V. B []) 1.7 V. C []) -0.7 V. D [v]) 0.7 V.

5 16) The most common type of diode failure is a(n). A [v]) open B []) short C []) resistive D []) all of these 17) What occurs when a conduction-band electron loses energy and falls back into a hole in the valence band? A [ ]) doping B [v]) recombination C [ ]) generation D [ ]) diffusion 18) A silicon diode is forward-biased. You measure the voltage to ground from the anode at, and the voltage from the cathode to ground at. A [ ]) 0 V, 0.3 V B [v]) 2.3 V, 1.6 V C [ ]) 1.6 V, 2.3 V D [ ]) 0.3 V, 0 V 19) The term bias in electronics usually means A []) the value of ac voltage in the signal. B []) the condition of current through a pn junction C [v]) the value of dc voltages for the device to operate properly. D []) the status of the diode. 20) Which capacitance dominates in the reverse-bias region? A [v]) depletion B []) conversion C []) Diffusion D []) None of the above

6 21) How many orbiting electrons does the germanium atom have? A []) 4 B []) 14 C [v]) 32 D []) 41 22) What unit is used to represent the level of a diode forward current IF? A []) pa B []) na C [v]) ma D []) A 23) The diffused impurities with valence electrons are called donor atoms. A [v]) 5 B []) 4 C []) 3 D []) 0 24) What is the range of the operating voltage level for LEDs? A []) 5-12 mv B [v]) V C []) 5-12 V D []) V 25) At what kind of operating frequency diffusion or transition is a capacitor represented in parallel with the ideal diode? A [ ]) Low frequency B [ ]) Moderate frequency C [ ]) Mid frequency D [v]) Very high frequency 26) Which of the following devices can check the condition of a semiconductor diode? A [ ]) Digital display meter (DDM)

7 B [ ]) Multimeter C [ ]) Curve tracer D [v]) All of the above 27) How many valence electrons does a silicon atom have? A []) 2 B [v]) 4 C []) 6 D []) 8 28) Calculate the power dissipation of a diode having ID = 40 ma. A [v]) 28mW B [ ]) 28W C [ ]) 280mW D [ ]) Undefined E [ ]) HINTS-By default take it Si diode then V=0.7 Given I=40 ma Then power=vi=0.7*40=28mw NOTE-IF Ge diode then take V=0.3 29) Which of the following elements is most frequently used for doping pure Ge or Si? A []) Boron B []) Gallium C []) Indium D [v]) All of the above 30) Which of the following ratings is true? A [ ]) Si diodes have higher PIV and narrower temperature ranges than Ge diodes. B [v]) Si diodes have higher PIV and narrower temperature ranges than Ge diodes. C [ ]) Si diodes have lower PIV and narrower temperature ranges than Ge diodes. D [ ]) Si diodes have lower PIV and wider temperature ranges than Ge diodes. 31) In what state is a silicon diode if the voltage drop across it is about 0.7 V? A [ ]) No bias

8 B [v]) Forward bias C [ ]) Reverse bias D [ ]) Zener region 32) Schottky diodes are also known as A []) PIN diodes. B [v]) hot carrier diodes. C []) step-recovery diodes. D []) tunnel diodes. 33) Zener diodes with breakdown voltages less than 5 V operate predominantly in what type of breakdown? A [ ]) avalanche B [v]) zener C [ ]) varactor D [ ]) Schottky 34) The Schottky diode is used A []) in high-power circuits. B []) in circuits requiring negative resistance. C [v]) in very fast-switching circuits. D []) in power supply rectifiers. 35) You have an application for a diode to be used in a tuning circuit. A type of diode to use might be A [ ]) an LED. B [ ]) a Schottky diode. C [ ]) a Gunn diode. D [v]) a varactor 36) What kind of diode is formed by joining a doped semiconductor region with a metal? A [ ]) laser B [ ]) tunnel

9 C [ ]) pin D [v]) Schottky 37) Which diode employs graded doping? A []) zener B []) LED C []) tunnel D [v]) step-recovery 38) LEDs are made out of A []) silicon. B []) germanium. C [v]) gallium. D []) silicon and germanium, but not gallium. 39) The normal operating region for a zener diode is the A []) forward-bias region. B []) reverse-bias region. C []) zero-crossing region. D [v]) reverse-breakdown region. 40) An 8.2 V zener has a resistance of 5. The actual voltage across its terminals when the current is 25 ma is A [ ]) 8.2 V. B [ ]) 125 mv. C [v]) V. D [ ]) V. E [ ]) HINTS-Voltage drop across zener diode=5*25=125mv=0.125v Now total terminal voltage= = ) What diode is used in seven-segment displays? A [ ]) zener B [v]) LED

10 C [ ]) laser D [ ]) Schottky 42) Zener diodes with breakdown voltages greater than 5 V operate predominantly in what type of breakdown? A [v]) avalanche B [ ]) zener C [ ]) varactor D [ ]) Schottky 43) Back-to-back varactor diodes are used for what reason? A []) over-voltage protection B []) a wider tuning range C [v]) to eliminate harmonic distortion D []) no reason; only zeners are used in a back-to-back configuration 44) A tunnel diode is used A []) in high-power circuits. B [v]) in circuits requiring negative resistance C []) in power supply rectifiers D []) in very fast-switching circuits. 45) A laser diode normally emits A []) coherent light. B []) monochromatic light. C [v]) coherent and monochromatic light. D []) neither coherent nor monochromatic light. 46) A varactor is a pn junction diode that always operates in -bias and is doped to the inherent capacitance of the depletion region. A [ ]) forward, maximize B [v]) reverse, maximize C [ ]) reverse, minimize

11 D [ ]) forward, minimize 47) What type of diode circuit is used to clip off portions of signal voltages above or below certain levels? A [v]) clipper or limiter B [ ]) clamper C [ ]) IC voltage regulator D [ ]) none of the above 48) Each diode in a center-tapped full-wave rectifier is -biased and conducts for of the input cycle. A [ ]) forward, 90º B [ ]) reverse, 180º C [v]) forward, 180º D [ ]) reverse, 90º 49) The output frequency of a full-wave rectifier is the input frequency. A []) one-half B []) equal to C [v]) twice D []) one-quarter 50) What type of diode circuit is used to add or restore a dc level to an electrical signal? A []) clipper or limiter B [v]) clamper C []) IC voltage regulator D []) none of the above 51) Electrons in p-type material of a semi-conductor are called as A []) either minority carriers or majority carriers B [v]) minority carriers C []) majority carriers D []) valance carriers

12 52) Depletion region of a p-n junction is formed A []) During Reverse bias B []) During Forward bias C [v]) During Manufacturing D []) During Heating 53) A 555 IC is used to produce A []) counter B []) register C [v]) clock D []) byte 54) Example of donor atom is A []) Germinium B []) Silicon C []) Both A and B D [v]) Antimony 55) Donors to a semiconductor material is A [v]) Pentavalant B []) Trivalant C []) Divalant D []) Tetravalant 56) Acceptors impurities are of material A []) n-type B [v]) p-type C []) solid D []) Both A and B 57) The majority carriers in the emitter of a PNP transistor are

13 A [v]) holes. B []) free electrons. C []) trivalent atoms. D []) pentavalent atoms. 58) Darlington connection is achieved in 2 transistors by connecting A []) both emitter. B [v]) both collector. C []) both base. D []) grounding both collector. 59) The current gain of a pnp transistor is A []) the negative of the npn current gain. B []) the collector current divided by the emitter current. C []) near zero. D [v]) the ratio of collector current to emitter current. 60) Which material behave like perfect insulators at low temperatures & conductor at higher temperature? A [ ]) Si B [ ]) Ge C [ ]) GaAs D [v]) All the above 61) What is the charge of mobile charge carriers of holes? A []) Negatively charged B []) No charged C [v]) Positively charged D []) None of the above 62) Diode is also called as: A [ ]) Amplifier B [v]) Rectifier

14 C [ ]) Resistance D [ ]) Reactance 63) Which is the third region where no charge carriers are present when n-type and p-type are attached together? A [ ]) Forward region B [v]) Depletion region C [ ]) Reversed region D [ ]) None of the above 64) What will be the Potential barrier for Ge Diode? A []) 0.7V B [v]) 0.3V C []) 0.5V D []) 0.03V 65) When will be the P-N junction is formed? A []) In reverse biased region B []) In depletion region C [v]) Two opposite doped materials D []) None of the above 66) If temperature increases then conductivity of a semiconductor is... A []) Decreases B [v]) Increases C []) Constant D []) None of the above 67) What is an energy gap? A []) Energy band in which electrons can move freely B []) Energy level at which an electron can exist C [v]) Space between two orbital shells D []) None of the above

15 68) What is the range of energy band gap of semiconductors? A [v]) 1-3 ev B []) 0 ev C []) ev D []) ev 69) Which impurity is added into semiconductor to increase its conductivity? A [v]) extrinsic B []) intrinsic C []) doping D []) None of the above 70) What will be the result if pentavalent impurity is added to pure germanium or silicon? A [v]) N-type semiconductor B []) Intrinsic semiconductor C []) P-type semiconductor D []) None of the above 71) Which of the following is the pentavalent material? A []) Boron B []) Neon C [v]) Arsenic D []) Gallium 72) How will be the extrinsic semiconductor act at room temperature? A [v]) Poor conductor B []) Medium Conductor C []) Conductor D []) None of the above 73) Which of the following is trivalent impurity?

16 Electronics Devices And Circuits Objective Type Questions With Answer 50% OFF Publisher : Faculty Notes Author : Panel Of Experts Type the URL : Get this ebook

Electronic Circuits I. Instructor: Dr. Alaa Mahmoud

Electronic Circuits I. Instructor: Dr. Alaa Mahmoud Electronic Circuits I Instructor: Dr. Alaa Mahmoud alaa_y_emam@hotmail.com Chapter 27 Diode and diode application Outline: Semiconductor Materials The P-N Junction Diode Biasing P-N Junction Volt-Ampere