[ELECS] TRANSISTORS

108. Which of the following statements is not correct A. For normal operation of a JFET, Vos > VP B. Drain and source terminal can be interchange C. Channel resistance increases as IDs increases D. I Dmax= Ipss can be attained when Vos=0

: A

109. When the transistor is operated at higher frequency, the appropriate model to be used A. Hybrid pi or Giacolleto model B. Ebers-Moll model C. Hybrid parameter model D. Z parameter model

: A

110. The depletion region between the PN junction of a JFET will when it increases. A. Skew B. Increase C. Decrease D. Not change

: A

111. Which is beta's current ratio? A. I/IB B. Ille C. IB/IE D. IF/IB

: A

113. What does a reading of a large or smail resistance in forward- and reverse-biased conditions indicate when checking a transistor using an ohmmeter? A. Faulty device B. Good device C. Bad ohmmeter D. None of the above

: A

119. What model is appropriate to use if for a given transistor amplifier, beta is the only parameter available and we want to solve for the amplifiers input and output impedance or resistance and its voltage and current model. A. Re model or dynamic resistance model B. Ebers-Moll model C. Hybrid parameter model D. Hybrid pi or Giacolleto model

: A

120. Usually the substrate is connected to A. Source B. Drain C. Gate D. Either source or drain

: A

127. An ideal value of stability factor is A, 1 B. 100 C. 200 D. more than 200

: A

137. Why does the BC junction heat more than the EB? A. Higher R with same I B. Higher I with same R C. Higher R with higher I D. Lower R with lower I

: A

138. Which is cheaper? A, JFET B. BJT C. MOSFET D. UJT

: A

142. For a silicon transistor, when a base- emitter junction is forward-biased, it has a nominal voltage drop of A. 0.7 V. B. 0.3 V. C. 0.2 V. D. Vcc.

: A

151. With a PNP circuit, the most positive voltage is probably: A. ground B. Vc C. VBE D. Vcc

: A

154. Refer to this figure. In the voltage- divider biased npn transistor circuit, if R2 opens, the transistor is + Vcc R, Rc Bec R2 RE A. saturated. B. cutoff. C. nonconducting. D. shorted

: A

155. Which JFET configuration would connect a high-resistance signal source to a low-resistance load? A. source follower B. common-source C. common-drain D. common-gate

: A

159. Layer of the transistor that is heavily doped A. Emitter B. Base C. Collector D. Emitter and Collector

: A

161. The symbol hfe is the same as: A. Врс B. DC C. hi-fi D. Bad

: A

170. What is the level of Ig in an FET? A. Zero amperes B. Equal to Id C. Depends on Vds D. Undefined

: A

173. For the BJT to operate in the saturation region, the base-emitter junction must be -biased and the base-collector junction must be -biased. A. forward, forward B. forward, reverse C. reverse, reverse D, reverse, forward

: A

174. The most stable biasing technique used is the A. voltage-divider bias. B. base bias. C. emitter bias. D. collector bias.

: A

175. When VGS =0 V, a JFET is: A, saturated B. an analog device C. an open switch D. cut off

: A

179. What happens to a BJT if there is no Bypass Capacitor 103 A. The voltage gain decreases B. The voltage gain increases C. It becomes stable D. Nothing happens

: A

18. What is the leakage current flowing in a common emitter configuration A. Iceo B. Icbo C. Ices D. Icbs

: A

180. The ideal drain resistance in the ohmic region of a depletion-mode device equals the pinch-off voltage divided by the A. Drain current B. Gate current C. Ideal drain current D. Drain current for zero gate voltage

: A

189. The output resistance in a common base amplifier is A. High B. Medium C. Low D. Zero

: A

19. In the zero signal conditions, transistor sees load A. DC B. AC C. Both dc and AC D. none of the choices

: A

200. In an n-channel enhancement type MOSFET, the gate voltage should be with respect to the Source in order to produce or enhance a channel. A, Positive B. Negative C. Equal D. Either positive or negative

: A

202. Which of the following is true for an npn or pnp transistor? A. IE=IB + IC B. IB = IC + le C. Ic = IB + IE D. none of the above

: A

204. Which transistor bias circuit arrangement has poor stability because its Q-point varies widely with Boc? A. bas bias B. collector-feedback bias C. voltage-divider bias D. emitter bias

: A

205. When the JFET is no longer able to control the current, this point is called the: A. breakdown region danletion region D C. saturation point D. pinch-off region

: A

206. What is the voltage gain of a feedback pair connection? A. 1 B. -1 C. 100 D. -100

: A

211. For a C-C configuration to operate properly, the collector-base junction should be reverse biased, while forward bias should be applied to which junction? A. collector-emitter B. base-emitter C. collector-base D. cathode-anode

: A

215. With a JFET, a ratio of output current change against an input voltage change is called: A. transconductance B. siemens C. resistivity D. gain

: A

217. Transistors use what form of an equivalent circuit A Norton's B. Thevenin's C. Voltage-form D. none of these

: A

233. Refer to the given figure. The most probable cause of trouble, if any, from these voltage measurements is +9v R1 22 ka Rc 3.3 ko 6.56 R2 8.2 km 1 ko Boc - 120 A. the base-emitter junction is open. B. Re is open. C. a short from collector to emitter. D. no problems.

: A

237. A very popular connection of two bipolar junction transistors for operations as one superbeta transistor is the A. Darlington B. Cascode C. Cascade D. Feedback pair

: A

248. Compared to a bipolar transistor, the JFET has much less A. voltage gain B. input resistance C. supply voltage D. Current

: A

32. VCE approximately equals when a transistor switch is cut off. A. Vcc B. VB C. 0.2 V D. 0,7 V

: A

39. If a transistor amplifier feeds a load of low resistance, then voltage gain will be A. low B. high C. very high D. moderate

: A

4. How many carriers participate in the injection process of a unipolar device? A. 1 B, 2 C. O D. 3

: A

42. The input resistance, Rin of a common- collector amplifier, consists of Vin link . A. Rin Re X AC Current Gain B. Rin C. Ri Re X a D. none of the above

: A

44. How many individual pnp silicon transistors can be housed in a 14-pin plastic dual-in-line package? A, 4 B, 7 C. 10 D. 14

: A

46. In an n-channel JFET, what will happen at the pinch-off voltage? A. the value of Vos at which further increases in Vos will cause no further increase in ID B. the value of Vas at which further decreases in VGS will cause no further increases in ID C. the value of VDG at which further decreases in VDG will cause no further increases in ID D. the value of Vos at which further increases in Vos will cause no further increases in ID

: A

48. Bipolar junction transistor is considered as a bipolar device due to the fact that both holes and electrons flow during its operation. For FET, only one carrier is involved and is therefore called a unipolar device. The carrier used in FET is A. Either holes and electrons B. Majority carriers C. Minority carriers D. None of these

: A

52. The signal voltage gain of an amplifier, AV, is defined as AVout A. Av = Vin B. Av = Ic x RC RL C. Av D. Av =

: A

58. A BJT is a current-controlled current source device while a JFET is a A. voltage-controlled current source B. current-controlled voltage source C. voltage-controlled voltage source D. transconductance-controlled

: A

65. "U" shaped, opposite-polarity material built near a JFET-channel center is called the: A. gate B. block C. drain D. heat sink

: A

66. One advantage of voltage-divider bias is that the dependency of drain current, ID, on the range of Q points is A, reduced B. increased C. not affected D. none of the above

: A

75. In the constant-current region, how will the IDS change in an n-channel JFET? A. As Vos decreases Ip decreases. B. As Vos increases Ip increases. C. As Vos decreases Ip remains constant. D. As Vos increases Ip remains constant.

: A

87. The leakage current in CE arrangement is that in CB arrangement. A. more than B. less C. the same as D. none of the above

: A

89. Equivalent circuit commonly used in transistors small signal analysis. A. Hybrid parameter model B. Ebers-Moll model C. Hybrid-pi model D. T-equivalent model

: A

93. In a JFET A. drain current is very nearly equal to source current B. drain current is much less than source current C. drain current may be equal to or less than source current D. drain current may be even more than source current

: A

97. The CE stage with a feedback resistor in the emitter circuit. A. Swamped amplifier B. CE amplifier C. Differential amplifier D. Class B push pull amplifier

: A

99. T-equivalent circuit is considered as a representation A. Physical B. Black box C. Four-terminal network D. General

: A

B. C. D. ac 150 dep 167. When radio-frequency passes through a semiconductor diode with low junction capacitance: A. Harmonics are generated B. The diode oscillates C. The diode will not conduct D. The diode acts like a resonant circuit

: A

RC RL 53. What range of resistor values would you get when checking a transistor for forward- and reverse-biased conditions by an ohmmeter? A. 1002 to a few ks2, exceeding 100 ks2 B. Exceeding 100 k92, 100 to a few k12 C. Exceeding 100 ks2, exceeding 100 k92 D. 100Ω to a few kΩ, 1ooΩ to a few kΩ

: A

] 1 hi 166. What is the typical value of the current gain of a common-base configuration? A. Less than 1 B. Between 1 and 50 C. Between 100 and 200 D. Undefined

: A

a 105. What is the input impedance of common-gate configured JFET? A. very low B. low C. high D. very high

: A

a 116. When BJT is operated under saturated condition A. both junctions are forward biased B. both junctions are reverse biased C. CB junction is forward biased and EB junction is reverse biased D. EB junction is forward biased and CB junction is reverse biased

: A

a 130. For BJT amplifier, the external emitter resistor R_E can greatly increase the input resistance of the amplifier. Ideally, what is the effect of the external source resistance RS in JFET amplifier to its input resistance? A. No effect B. Increase C. Decrease D. Impossible to say

: A

a 14. What are the ranges of the ac input and output resistance for common-base configuration? A. 10ohm-100 ohm, 50 Kohm -1 Mohm B. 50 Kohm - 1 Mohm, 10 ohm-100ohm C. 10 ohm-100 Kohm, 50ohm - 1 Kohm D. None of the above

: A

a 15. The common-source JFET amplifier has: A. a very high input impedance and relatively low voltage gain B. a high input impedance and a very high voltage gain C. a high input impedance and a voltage gain less than i D. no voltage gain

: A

a 226. What is the range of the input impedance of common-base configuration? A. A few ohms to a maximum of 50 N Β. 1 kΩ to 5 kΩ C. 100 kg to 500 kg D. 1 ΜΩ to 2 ΜΩ

: A

a 71. The ends of a load line drawn on family of curves determine: A, saturation and cutoff B. the operating point C. the power curve D. the amplification factor

: A

an emitter 41. In a C-E configuration, resistor is used for: A. stabilization B. ac signal bypass C. collector bias D. higher gain

: A

as 228. In enhancement-type MOSFETs, the regions are used for operation as a switch. A. triode and saturation B, cut-off and saturation C. saturation and active D. cut-off and triode

: A

circuit 129. Most transistor equivalent employs resistances and A. Current source B. Voltage source C. Stiff voltage source D. Stiff current source

: A

coltag 169. The graph of the product of collector emitter voltage (V_CE) and collector current (I_C) in the transistor characteristic curve. A. Maximum power curve B. Minimum power curve C. Saturation power curve D. Breakdown curve

: A

is used to 81. The C-B configuration provide which type of gain? A. voltage B. current C. resistance D. power

: A

of re the in h-parameters common-base 126. Which corresponds to configuration? A. hib B. hib C. hrb D. hob

: A

types of bipolar 162. What are the two junction transistors? A. npn and pnp B. pnn and nnp C. ppn and nnp D. pts and stp

: A

when 149. A semiconductor material heavily doped A. Produces more free electrons B. Increases its resistance C. Decreases its conductivity D. Decreases its resistance

: A

10. In a semiconductor technology, the characteristics of a transistor in cut-off refers to a condition when A. Transistor is at its operating point B. No current flows emitter to collector C. There is no base current D. Maximum current flows from emitter to collector

: B

107. If the emitter resistance of a common emitter transistor is unbypassed, the emitter resistance provides A. Regenerative feedback B. Negative feedback C. No feedback at all D. Instability

: B

115. JFET terminal "legs" are connections to the drain, the gate, and the: A. channel B. source C. substrate D. cathode

: B

121. A collector characteristic curve is a graph showing: A. emitter current (IE) versus collector- emitter voltage (Vce) with (VBB) base bias voltage held constant B. collector current (Ic) versus collector- emitter voltage (VCE) with (VBB) base bias voltage held constant C. collector current (Ic) versus collector- emitter voltage (Vc) with (VBB) base bias voltage held constant D. collector current (Ic) versus collector- emitter voltage (Vcc) with (VBB) base bias voltage held constant

: B

124. At what region of operation is the base-emitter junction forward biased and the base-collector junction reverse biased? A. Saturation B. Linear or active C. Cutoff D. None of the above

: B

128. The junction field effect transistor's (JFET) gate element corresponds very closely in operation with (a) what part of a conventional transistor and (b) what part of the vacuum tube? A. (a) Emitter (b) Cathode B. (a) Base (b) Grid C. (a) Base (b) Cathode D. (a) Collector (b) Plate

: B

131. With low-power transistor packages, the base terminal is usually the: A. tab end B, middle C. right end D. stud mount

: B

135. With the E-MOSFET, when gate input voltage is zero, drain current is: A, at saturation B. zero C. Ipss D. widening the channel

: B

136. Which of the following is referred to as the reverse transfer voltage ratio? A. h; B.hr C. he D. ho

: B

144. Which of the following currents nearly equal to each other? A. IB and Ic B. IE and Ic C. IB and IE D. IB, I, and IE

: B

156. For a common-emitter amplifier, the purpose of swamping is A. to minimize gain. B. to reduce the effects of r'e C. to maximize gain. D. no purpose.

: B

163. For the typical transistor amplifier in the active region, VCE is usually about % to % of Voc. A. 10, 60 B. 25, 75 C. 40, 90 D. 50, 60

: B

17. What separates the three regions in a BJT? A. N region and P region B. Two PN junctions C. Metal conductors D. Space

: B

171. Most of the electrons in the base of an NPN transistor flow: A, out of the base lead B. into the collector C. into the emitter D. into the base supply

: B

186. The model fails to account for the output impedance level of the device and the feedback effect from output to input. A. hybrid equivalent В. Ге C. ß D. Thevenin

: B

199. What is the term for partially bypassing the capacitor in a voltage divider bias BJT? A. Parby B. Swamping C. Cleaning D. Clearing

: B

2. The input resistance of the base of an emitter-follower is usually A. very low B. very high C. shorted to ground D. open

: B

207. To increase the minority carrier current the ________________________ must be increased. A. Dopants B. Temperature C. Reverse bias D. Forward bias

: B

209. The input impedance of the base of an emitter follower is usually A. low B. high C. shorted to ground D. open

: B

212. What is the order of doping, from heavily to lightly doped, for each region? A. base, collector, emitter B. emitter, collector, base C. emitter, base, collector D. collector, emitter, base

: B

216. A common-emitter amplifier has voltage gain, current gain, power gain, and input impedance. A. high, low, high, low B. high, high, high, low C. high, high, high, high D. low, low, low, high

: B

22. Base bias provides A, a very stable Q point B. a very unstable Q point C. no current gain D. zero current in the base and collector circuits

: B

222. In what range of voltages is the transistor in the linear region of its operation? A. 0 < VCE B. 0.7 < VCE < VCE(max) C. V CE(max) > VCE D. none of the above

: B

224. Refer to the given figure. The most probable cause of trouble, if any, from these voltage measurements would be +12V R1 10 ka Series 12 1.1 0.4 V R2 1 kn RE 100 ko Boc = 180 A. the base-emitter junction is open. B. Re is open. C. a short from collector to emitter. D. no problems.

: B

236. The advantage that a Sziklai pair has over a Darlington pair is A. higher current gain. B. less input voltage is needed to turn it on. C. higher input impedance. D. higher voltage gain.

: B

244. Voltage-divider bias has a relatively stable Q-point, as does A. base bias. B. collector-feedback bias. C. both of the above D. none of the above

: B

245. The type of bias most often used with E-MOSFET circuits is: A, constant current B. drain-feedback C. voltage-divider D. zero biasing

: B

25. Refer to this figure. In the voltage- divider biased npn transistor circuit, if Ri opens, the transistor is + vec RI Rc Boc Rz RE A, saturated. B. cutoff. C. nonconducting. D. shorted

: B

250. In an insulated gate FET, the polarity of inversion layer is the same as that of A, minority carriers in source B. majority carriers in source C. charge on gate electrode D. minority carriers

: B

38. The main reason for the variation of amplifier gain with frequency is A. Due to interstage transformer B. the presence of capacitance both external and internal C. The logarithmic increase in its output D. The miller effect

: B

47. The configuration noted for its stability in radio-frequency power amplifiers is the: A. common-emitter circuit B. common-base circuit C. common-collector circuit D. emitter-follower circuit

: B

50. FET's are more temperature stable than BJTs and are usually BJT's A. Bigger than B. Smaller than C. Same as D. None of the above

: B

51. Voltage-divider bias provides: A. an unstable Q point B. a stable Q point C. a Q point that easily varies with changes in the transistor's current gain D. a Q point that is stable and easily varies with changes in the transistor's current gain

: B

72. An emitter-follower has a voltage gain that is A, much less than one B. approximately equal to one C. greater than one D. zero

: B

78. A JFET is similar in operation to what other device? A. Diode B. Triode C. Triac D. UJT

: B

79. The value of collector load RC in a transistor amplifier is the output impedance of the transistor. A. the same as B. less than C. more than D. none of the choices

: B

80. The current through the channel of a JFET is directly affected by all of the following except: A. Drain voltage B. Transconductance C. Gate voltage D. Gate Bias

: B

A will 76. produce a change in Vps change in I». A. small, large B. large, small C. large, large D. small, small

: B

B I current area 148. An FET has constant which lies between A. Idss and o B. Breakdown and pinch off C. Saturation and cutoff D. Pinch off cutoff

: B

In current is 191. a transistor, collector controlled by: A. collector voltage B. base current C. collector resistance D. all of the above

: B

] 4 223. Which transistor bias circuit arrangement provides good stability using negative feedback from collector to base? A. base bias B. collector-feedback bias C. voltage-divider bias D. emitter bias

: B

a 187. The gain of a common-gate amplifier is A. less than 1 B.less than that of common-source amplifier C. less than that of a common-drain amplifier D. more than that of a common-source amplifier

: B

are -terminal 123. Transistors devices. A. 2 B. 3 C. 4 D. 5

: B

base- 84. For the BJT to operate in the active (linear) region, the base-emitter junction must be -biased and the collector junction must be biased. A. forward, forward B. forward, reverse C. reverse, reverse D. reverse, forward

: B

best storage aid for 198. Which is the MOSFETs? A. Styrofoam B. aluminum foil C, refrigerator D. plastic

: B

can 190. A depletion MOSFET (D MOSFET) operate with which of the following gate - to - source voltage? A. Zero B, Positive C. Negative A. A only B, A, B and C C. A and B only D, A and C only

: B

can 5. The input resistance of the base of a voltage-divider biased transistor be neglected A, at all times. B. only if the base current is much smaller than the current through R2 (the lower bias resistor). C. at no time. D. only if the base current is much larger than the current through R2 (the lower bias resistor).

: B

can as an 68. An FET act excellent amplifier because A. It has a low input impedance and a high output impedance B. It has a high input impedance and a low output impedance C. It has a very high voltage gain and a low noise level D. Smaller size, longer life, and lower efficiency

: B

data sheet usually 182. A transistor identifies Boc as A. hre. B. hre. C. Ic. D. Vce.

: B

for the Darlington 106. The current gain connection is A. Bi · (B2/2) B. Bi ·B2 C. B/B2 D. Bi · (B2 1)

: B

. 3 43. In the active region, while the collector- base junction is -biased, the base- emitter is -biased. A. forward, forward B. forward, reverse C. reverse, forward D. reverse, reverse

: C

104. In a fixed-bias circuit, which one of the stability factors overrides the other factors? A. S(Ico) B. S(VBE) C. S(B) D. Undefined

: C

11. Three different Q points are shown on a dc load line. The upper Q point represents the: A. minimum current gain B. intermediate current gain C. maximum current gain D. cutoff point

: C

112. For normal operation of a pnp BJT, the base must be with respect to the emitter and with respect to the collector. A. positive, negative B. positive, positive C. negative, positive D. negative, negative

: C

117. Networks that are quite stable and relatively insensitive to temperature variations have stability factors A. High B. Medium C. Low D. Infinite

: C

118. The channel of a JFET is found A. Between the gate and drain B. Between the gate and source C. Between the drain and source D. Between the input and output

: C

12. The phase difference between the input and output ac voltage signals of a common- emitter amplifier is A. 0° B. 90° C. 180° D. 360°

: C

122. When a transistor is used as a switch, it is stable in which two distinct regions? A. saturation and active B. active and cutoff C. saturation and cutoff D. none of the above

: C

125. A very simple bias for a D-MOSFET is called: A. self biasing B. gate biasing C. zero biasing D. voltage-divider biasing

: C

13. How many layers of material does a transistor have? B. 2 C. 3 D. 4

: C

134. In a voltage-divider circuit, which one of the stability factors has the least effect on the device at very high temperature? A. S(Ico) B. S(VBE) C. S(B) D. Undefined

: C

140. When reverse bias is applied to the gate lead of a JFET, what happens to (a) source to drain resistance of the device and (b) current flow? A. (a) Decreases (b) Decreases B. (a) Decreases (b) Increases C. (a) Increases (b) Decreases D. (a) Increases (b) Increases

: C

143. The early effect in a BJT is caused by A. fast turn on B. fast turn off C. large collector base reverse bias D. large emitter base forward bias

: C

150. Reverse bias of JFET produces a depletion region within the channel thus channel resistance A. Maintaining B. Decreasing C. Increasing D. Cancelling

: C

152. What does Boc vary with? A. Ic B. °C C. both Ic and °C D. Ic, but not °C

: C

153. Which of the following voltages must have a negative level (value) in any npn bias circuit? A. VBE B. V ce C. VBC D. None of the above

: C

176. An emitter-follower is also known as a A. common-emitter amplifier. B. common-base amplifier. C. common-collector amplifier. D. Darlington pair.

: C

177. A typical power-supply voltage for a bipolar-transistor circuit is A. 0.3 V B. 1.0 V C. 9.0 V D. 117 V

: C

181. Total emitter current is: A. IE - Ic B. Ic+IE C. IB + Ic D. IB - Ic

: C

188. When the drain-source voltage is less than the proportional pinch-off voltage, a depletion mode device acts as a A. Bipolar transistor B. Current source C. RESISTOR D. Battery

: C

193. The saturation region is defined by Vce V CEsat. A. > B. < C. <= D. >=

: C

194. Refer to this figure. In the voltage- divider biased npn transistor circuit, if Rc opens, the transistor is + Vec RC R1 boc R2 RE A, saturated. B. cutoff. C. nonconducting. D. shorted

: C

196. You have a need to apply an amplifier with a very high power gain. Which of the following would you choose? A. common-collector B. common-base C. common-emitter D. emitter-follower

: C

21. A current ratio of Idle is usually less than one and is called: A. beta B. theta C. alpha D. omega

: C

218. What is the unit of the parameter ho? A. Volt B, Ohm C, Siemen D. No unit

: C

219. The collector feedback bias A. Based on the principle of positive feedback B. Based on beta multiplication C. Based on the principle of negative feedback D. Not very stable

: C

225. Which type of JFET bias requires a negative supply voltage? A. feedback B. source C. gate D. voltage divider

: C

229. What is the purpose of the capacitor between the two resistors in the collector de feedback configuration? A. To reduce dc current B. It has no effect whatsoever C. To put the resistor to its left in the input circuit and the resistor to its right in the output circuit and the resistor to its right in the output circuit in the ac domain D. None of the above

: C

230. The input to a CMOS gate appears primarily as A. Low resistance B. High resistance C. Capacitor D. Inductor

: C

232. The magnitude of dark current in a phototransistor usually falls in what range? A. mA Β. μΑ C. NA D. PA

: C

234. At satu tion the value of Vce is nearly and Ic = A. zero, zero B. Vcc, Ic(sat) C. Zero, I(sat) D. V cc, zero

: C

238. The maximum current permitted to flow in the forward direction in the form of non-recurring pulses. A. Peak current B. Peak forward current C. Maximum forward current D. Maximum surge current

: C

24. What is the most frequently encountered transistor configuration? A. Common-base B. Common-collector C. Common-emitter D. Emitter-collector

: C

246. What is the typical range of the output impedance of common-emitter configuration? A. 10 N2 to 100 m2 Β. 1 kΩ to 5 kΩ C. 40 K to 50 kg D. 500 kΩ to 1 kΩ

: C

247. In voltage divider biased npn transistor, if the lower voltage divider resistor (the one connected to ground) opens A. The transistor is cutoff B. The transistor may be driven into cutoff C. The transistor may be driven into saturation D. The collector current will decrease

: C

249. Common base amplifier has compared to common emitter and common collector amplifier A. A higher input resistance B. A larger current gain C. A lower input resistance D. A larger voltage gain

: C

28. In power transistors, the metal mounting tab or case is connected to which transistor region? A, Base B. Emitter C. Collector D. None of the above

: C

29. The purpose of emitter capacitor (i.e. capacitor across RE) is to A. forward bias the emitter B. reduce noise the amplifier C. avoid voltage drop in gain D. none of the choices

: C

31. With the positive probe on an NPN base, an ohmmeter reading between the other transistor terminals should be: А. open B. infinite C. low resistance D. high resistance

: C

40. The type of bias used where only moderate changes in ambient temperature are expected? B. Self bias C. Fixed bias D. Limited bias

: C

45. When not in use, MOSFET pins are kept at the same potential through the use of: A. shipping foil B. nonconductive foam C. conductive foam D, a wrist strap

: C

49. The DC load of a transistor amplifier is generally that of AC load. A. the same as B. less than C. more than D. none of the choices

: C

55. D-MOSFETS are sometimes used in series to construct a cascode high- frequency amplifier to overcome the loss of; A. low output impedance B. capacitive reactance C. high input impedance D. inductive reactance

: C

57. A common-emitter amplifier circuit always contains A. a diode B. a JFET C. a bipolar transistor D. a transformer

: C

59. Ideally, a dc load line is a straight line drawn on the collector characteristic curves between A. The Q point and the cutoff B. The Q point and the saturation C. Cutoff V ce and saturated collector current D. At zero base current and ratio of collector current and beta

: C

6. The transconductance curve of a JFET is a graph of: A. Is versus Vos B. Ic versus VCE C. Id versus VGS D. IDX Ros

: C

62. VCE approximately equals when a transistor switch is in saturation. A. Vc B. VB C. 0.3 V D. 0.7 V

: C

67. What type of bias keeps the base bias constant and improves thermal stability? A. Self bias B. Fixed bias C. Combination bias D. Each of the above

: C

69. When the electron transit time through the base region is very short, this A, creates a higher potential barrier B. makes the transistor unable to amplify C. provides higher cut-off frequency D. provides a Zener effect

: C

7. It is the biasing of the BJT at room temperature with no voltage applied. A, unbias B. base bias C. zero bias D. VDB

: C

70. Since it is a voltage-controlled much like a vacuum tube, it is sometimes called the "solid-state vacuum tube" A. UJT B. phototransistor C. FET D. bipolar transistor

: C

73. In which region are both the collector- base and base-emitter junctions forward- biased? A, Active B. Cutoff C. Saturation D. All of the above

: C

74. Which component of the collector current IC is called the leakage current? A. Majority B. Independent C. Minority D. None of the above

: C

77. The disadvantage of a base bias is that A. It is very complex B. Provides a stable bias point C. It produces low gain D. It produces high leakage current

: C

8. The flow of electron is a NPN transistor when used in electronic circuit is from A. Collector to emitter B. Collector to base C. Emitter to collector D. Base to emitter

: C

86. A JFET amplifier provides a voltage gain of less than one. A. common-source B. common-gate C. common-drain D. cascode amplifier

: C

88. The transconductance curve is A. Linear B. Similar to the graph of a resistor C. Nonlinear D. Like a single drain curve

: C

91. The Q point on a load line may be used to determine: A. Vc B. Vcc C. VB D. Ic

: C

92. A JFET A, is a current-controlled device B. has a low input resistance C. is a voltage-controlled device D. is always forward-biased

: C

94. The cutoff region is defined by IB ___OA. A. > B. < C. < D.

: C

95. Ipss can be defined as: A. the minimum possible drain current B. the maximum possible current with Vos held at -4 V C. the maximum possible current with VGS held at O V D. the maximum drain current with the source shorted

: C

96. Which of the following configurations has the lowest output impedance? A. Fixed-bias B. Voltage-divider C. Emitter-follower D. None of the above

: C

98. In а source follower, which of the electrodes of the JFET receives the input signal? A. none of them B. the source C. the gate D, the drain

: C

9€ сс 147. The dc power input, in watts, to a bipolar-transistor amplifier circuit is equal to A. the base current in amperes times the base voltage in volts B. the base current in amperes times the emitter voltage in volts C. the collector current in amperes times the collector voltage in volts D. the emitter current in amperes times the base voltage in volts

: C

MULTIPLE CHOICE QUESTIONS 1. digital When transistors are used in circuits they usually operate in the: A. active region B. breakdown region C. saturation and cutoff regions D. linear region

: C

a 208. MESFET is more recent development and takes full advantage of high speed characteristics of A. Si B. Ge C. GaAs D. Ga

: C

a 235. How will D-MOSFET input impedance change with signal frequency? A. As frequency increases input impedance increases. B. As frequency increases input impedance is constant. C. As frequency decreases input impedance increases. D. As frequency decreases input impedance is constant.

: C

diode is for forward a C-E VBE 141. When a silicon biased, what is configuration? A. voltage-divider bias B. 0.4 V C. 0.7 V D. emitter voltage

: C

region 60. What JFET operating corresponds to saturation of BJT? A, cut-off B. saturation C. ohmic D. breakdown

: C

Α.Ν B. D C. In D. C Ansk 151. V 168. The drain current becomes constant when Vds exceeds for Vgs = 0 V A, Cutoff B. O V C. Ve D. Vad

: C

а channel E- 195. When is vertical MOSFET used? A. for high frequencies B. for high voltages C. for high currents D. for high resistances

: C

100. What is/are the function(s) of the coupling capacitors in an FET circuits? A. To create an open circuit for de analysis B. To isolate the de biasing arrangement from the applied signal and load C. To create a short circuit equivalent for ac analysis

: D

101. A transistor may be used as a switching device or as a: A. fixed resistor B. tuning device C. rectifier D. variable resistor

: D

102. What is the ratio of IC to IB? A. Boc B. hFE C. αpc D. either boc or hfe, but not apc

: D

103. Which of the following configurations can a transistor set up? A. Common-base B. Common-emitter C. Common-collector D. All of the above

: D

114. Which of the following is (are) related to an emitter-follower configuration? A. The input and output signals are in phase. B. The voltage gain is slightly less than 1. C. Output is drawn from the emitter terminal. D. All of the above

: D

132. The term BJT is short for A. base junction transistor. B. binary junction transistor. C. both junction transistor. D. bipolar junction transistor.

: D

133. Which of the following can be obtained from the last scale factor of a curve tracer? A, hpe B. Adc C. cac D. Bac

: D

139. Some advantages of transistors that is heavily doped A. Smaller and lightweight B. No heater, rugged and more efficient C. No warm up period and lower operating voltage D. All of these

: D

146. Which of the following conditions must be met to allow the use of the approximate approach in a voltage-divider bias configuration? A. Bre> 10R2 B. BRE > 10R2 C. BRE < 10R2 D. Bre < 10R2

: D

157. It is the voltage lying on the horizontal axis of the collector curve at which the base currents will intersect if they are projected to the left. A. thermal voltage B. cut-off voltage C. saturation voltage D. early voltage

: D

158. In a BJT circuit a pnp transistor is replaced by npn transistor. To analyse the new circuit A. all calculations done earlier have to be repeated B. replace all calculated voltages by reverse values C. replace all calculated currents by reverse values D. replace all calculated voltages and currents by reverse values

: D

16. Which transistor bias circuit arrangement provides good Q-point stability, but requires both positive and negative supply voltages? A. base bias B. collector-feedback bias C. voltage-divider bias D. emitter bias

: D

160. When the ac base voltage in a CE amplifier circuit is too high, the ac emitter current is A, zero B. constant C. alternating D. distorted

: D

165. How will electrons flow through a p- channel JFET? A. from source to drain B. from source to gate C. from drain to gate D. from drain to source

: D

172. The value of Boc A. is fixed for any particular transistor. B. varies with temperature. C. varies with Ic. D. varies with temperature and Ic.

: D

178. The pinch-off voltage has the same magnitude as the A. gate voltage B. drain-source voltage C. gate-source voltage D. gate-source cut-off voltage

: D

184. Emitter bias requires A. Only a positive supply voltage. B. only a negative supply voltage. C. no supply voltage. D. both positive and negative voltages.

: D

185. When applied input voltage varies the resistance of a channel, the result is called: A. saturization B. polarization C. cutoff D. field effect

: D

192. What is the ratio of Ic to le? А. врс B. Boc / (Boc + 1) C. apc D. either Boc / (Boc + 1) or @pc, but not Boc

: D

197. When the ohmmeter is connected with its negative terminal to the base of an NPN transistor and its positive terminal to the emitter, what is the most probable value that will displayed? A, ON Β. 1 k Ω C. 10 N D. 100 km

: D

20. The arrow in the symbol of a transistor indicates the direction of A. Electron current in the collector B. Donor ion current C. Electron current in the emitter D. Hole current in the emitter

: D

201. Often a common-collector will be the last stage before the load; the main function(s) of this stage is to: A. provide voltage gain B. provide phase inversion C. provide a high-frequency path to improve the frequency response D. buffer the voltage amplifiers from the low-resistance load and provide impedance matching for maximum power transfer

: D

203. Which of the following is (are) the application(s) of a transistor? A. Amplification of signal B. Switching and control C. Computer logic circuitry D. All of the above

: D

210. A MOSFET amplifier circuit which is composed of a self-biased CS amplifier in series with a voltage divider biased CG amplifier. A. NMOS B. PMOS C. CMOS D. cascode

: D

214. What is the most common bias circuit? A. base B. collector C. emitter D. voltage-divider

: D

220. In enhancement-type MOSFETs, the region is used if the FET is to operate as an amplifier. A. triode region B. diode region C. cut-off region D. saturation region

: D

23. Which of the following equipment can check the condition of a transistor? A. Current tracer B. Digital display meter (DDM) C. Ohmmeter (VOM) D. All of the above

: D

231. If a transistor operates at the middle of the dc load line, a decrease in the current gain will move the Q point: A. off the load line B. nowhere C. Up D. down

: D

239. The bypass capacitor in a common emitter configuration _____________________ the voltage gain A. Significantly decreases B. Significantly increases C. Slightly increases D. Slightly decreases

: D

240. When the two bases are grounded in a differential amplifier, the voltage across each emitter diode is A. One B. 0.8 V C. Not equal D. None of the preceding

: D

241. Which is the higher gain provided by a C-E configuration A. voltage B. current C. resistance D. power

: D

242. What is (are) common fault(s) in a BJT-based circuit? A. opens or shorts internal to the transistor B. open bias resistor(s) C. external opens and shorts on the circuit board D. all of the above

: D

243. What is the dc input resistance at the base of a BJT? A. PocRc B. Bix'(Rcl|Re) C. Bpore D. BpcRE

: D

26. The overall input capacitance of a dual- gate D-MOSFET is lower because the devices are usually connected: A. in parallel B. with separate insulation C. with separate inputs D. in series

: D

27. With proper bias applied to a transistor, what should be the relative resistance of (a) the emitter - base junction and (b) the base collector junction? A. (a) High (b) low B. (a) High (b) high C. (a) Low (b) low D. (a) Low (b) high

: D

3. The dc load line on a family of collector characteristic curves of a transistor shows the A. saturation region. B. cutoff region. C. active region. D. all of the above

: D

30. If a sinusoidal voltage is connected to the base of a biased non transistor and the resulting collector voltage is clipped near zero volts, the transistor is A. Being driven to saturation B. Being driven to cut off C. Operating nonlinearity D. A and C

: D

33. For what kind of amplifications can the active region of the common-emitter configuration be used? A. Voltage B. Current C. Power D. All of the above

: D

34. Which of the following regions is (are) part of the output characteristics of a transistor? A. Active B. Cutoff C, Saturation D. All of the above

: D

35. Junction Field Effect Transistors (JFET) contain how many diodes? A. 4 B. 3 C. 2 D. 1

: D

36. Which component is considered to be an "OFF" device? A. transistor B. JFET C. D-MOSFET D. E-MOSFET

: D

56. To get a negative gate-source voltage in a self-biased JFET circuit, you must use a A. negative gate supply voltage B. ground C. voltage divider D. source resistor

: D

61. To operate properly, a transistor's base- emitter junction must be forward biased with reverse bias applied to which junction? A. collector-emitter B. base-collector C. base-emitter D. collector-base

: D

63. What is (are) the component(s) of electrical characteristics on the specification sheets? A. On B. Off C. Small-signal characteristics D. All of the above

: D

64. What is the ratio of the total width to that of the center layer for a transistor? A. 1:15 B. 1:150 C. 15:1 D. 150:1

: D

82. The primary function of the bias circuit is to A. hold the circuit stable at Voc B. hold the circuit stable at Vin C. ensure proper gain is achieved D. hold the circuit stable at the designed Q- point

: D

83. Which of the following is (are) the terminal(s) of a transistor? A. Emitter B. Base C. Collector D. All of the above

: D

85. A MOSFET has how many terminals? A. 2 or 3 B. 3 C. 4 D. 3 or 4

: D

9. Vce is ________ in cutoff A. O V B. Minimum C. Equal to Vbb D. Equal to Vec

: D

90. The minimum value of VGS that will cause the drain current to drop to zero. A. O V B. thermal voltage C. 26 mV D. gate-source cutoff voltage

: D

B. 213. Clipping is the result of A. the input signal being too large. the transistor being driven into saturation. C. the transistor being driven into cutoff. D. all of the above

: D

] 1 221. The input/output relationship of the common-collector and common-base amplifiers is: A. 270 degrees B. 180 degrees C. 90 degrees D. O degrees

: D

a 164. Ideally, for linear operation, transistor should be biased so that the Q- point is A. near saturation. B. near cutoff. C. where IC is maximum. D. halfway between cutoff and saturation.

: D

a 183. Which of the following is assumed in the approximate analysis of voltage divider circuit? A. IB is essentially zero amperes. B. R and R2 are considered to be series elements. C. BRE > IOR2 D. All of the above

: D

an 145. When input signal reduces the channel size, the process is called: A, enhancement B. substrate connecting C. gate charge D. depletion

: D

are broken 54. Most specification sheets down into A. maximum ratings B. thermal characteristics C. electrical characteristics D. All of the above

: D

as 227. In a dc-voltage divider network the resistances should be large as possible B. the inductances must all be the same C. the capacitances must be in the right ratio D. the resistances should be small as possible

: D

protects 37. What is the layer which junctions in transistors called? A. Insulating B. Conducting C. Tendon D. Passivating

: D