MCQOPTIONS
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MCQOPTIONS
This section includes 261 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.
| 201. |
If emitter and collector terminals of BJT are interchanged by mistake, the amplification factor β in this mode will be: |
| A. | equal to β in normal mode |
| B. | higher than β in the normal mode |
| C. | lower than β in the normal mode |
| D. | zero |
| Answer» D. zero | |
| 202. |
If VB = 1V and VE = 1.7 V, β and Vc of the circuit will be ______. |
| A. | 165 and -1.75 V |
| B. | 150 and -2.75 V |
| C. | 0.994 and -1.75 V |
| D. | 180 and 2.75 V |
| Answer» B. 150 and -2.75 V | |
| 203. |
In the following circuit β is in the range of 8 to 40, Rc = 11 Ω, Vcc = 200 V, VB = 10 V. If the VCE(saturation) = 1.0 V and VBE(sat) = 1.5 V, over drive factor = 5. The value of power loss in the transistor is given by:(1) 35.07 W(2) 23.07 W(3) 13.07 W(4) 26.09 W |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» B. 2 | |
| 204. |
Identify the circuit given below: |
| A. | Common collector configuration |
| B. | Common emitter configuration |
| C. | Common diode configuration |
| D. | Common base configuration |
| Answer» C. Common diode configuration | |
| 205. |
A bipolar transistor has three leads: the base, collector, and emitter. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 206. |
VCE approximately equals ________ when a transistor switch is in saturation. |
| A. | VC |
| B. | VB |
| C. | 0.3 V |
| D. | 0.7 V |
| Answer» D. 0.7 V | |
| 207. |
Transistors are controlled to operate as a switch or to operate as a variable resistor. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 208. |
When troubleshooting a bipolar junction transistor using an ohmmeter, if one of the junctions reads low in both directions, the junction is shorted and the transistor is bad. If one of the junctions reads high in both directions, the junction is shorted and the transistor is good. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 209. |
In a common-base (C-B) amplifier, the output is 180 degrees out of phase with the input. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 210. |
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 |
| Answer» C. greater than one | |
| 211. |
The voltage measured from the collector to the emitter is the sum of the base-emitter voltage plus the collector-base voltage. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 212. |
The voltage gain of a transistor is inversely proportional to the change in output current. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 213. |
With a common-collector (C-C) amplifier the input is applied to the base and the output is taken from the emitter. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 214. |
If this circuit were used in a digital circuit, it would be a NOT gate. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 215. |
The polarity of VBE is such that it reverse biases the base-emitter junction. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 216. |
The three bipolar transistor circuit configurations are common-base, common-emitter, and emitter-follower. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 217. |
A common-emitter (C-E) is so called because the emitter is connected to both the input and output signals. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 218. |
The input/output relationship of the common-collector and common-base amplifiers is: |
| A. | 270 degrees |
| B. | 180 degrees |
| C. | 90 degrees |
| D. | 0 degrees |
| Answer» E. | |
| 219. |
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 |
| Answer» B. base-emitter | |
| 220. |
A transistor used in a digital circuit will have two operating states, which are cutoff and saturation. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 221. |
When a transistor is operating as a variable resistor it has transistance. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 222. |
The Q point on a load line may be used to determine: |
| A. | VC |
| B. | VCC |
| C. | VB |
| D. | IC |
| Answer» D. IC | |
| 223. |
With low-power transistor packages, the base terminal is usually the: |
| A. | tab end |
| B. | middle |
| C. | right end |
| D. | stud mount |
| Answer» C. right end | |
| 224. |
In a transistor, collector current is controlled by: |
| A. | collector voltage |
| B. | base current |
| C. | collector resistance |
| D. | all of the above |
| Answer» C. collector resistance | |
| 225. |
VCE approximately equals ________ when a transistor switch is cut off. |
| A. | VCC |
| B. | VB |
| C. | 0.2 V |
| D. | 0.7 V |
| Answer» B. VB | |
| 226. |
If an input signal ranges from 20–40 A (microamps), with an output signal ranging from .5–1.5 mA (milliamps), what is the ac beta? |
| A. | 0.05 |
| B. | 20 |
| C. | 50 |
| D. | 500 |
| Answer» D. 500 | |
| 227. |
With a PNP circuit, the most positive voltage is probably: |
| A. | ground |
| B. | VC |
| C. | VBE |
| D. | VCC |
| Answer» B. VC | |
| 228. |
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 |
| Answer» C. into the emitter | |
| 229. |
This is a PNP transistor. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 230. |
In this analog amplifier the input is in phase with the output. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 231. |
What is the current gain for a common-base configuration where IE = 4.2 mA and IC = 4.0 mA? |
| A. | 16.8 |
| B. | 1.05 |
| C. | 0.2 |
| D. | 0.95 |
| Answer» E. | |
| 232. |
A transistor may be used as a switching device or as a: |
| A. | fixed resistor |
| B. | tuning device |
| C. | rectifier |
| D. | variable resistor |
| Answer» E. | |
| 233. |
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 |
| Answer» C. a Q point that easily varies with changes in the transistor's current gain | |
| 234. |
In a BJT, the collector current is approximately equal to the base current. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 235. |
Total emitter current is: |
| A. | IE – IC |
| B. | IC + IE |
| C. | IB + IC |
| D. | IB – IC |
| Answer» D. IB ‚Äì IC | |
| 236. |
The phase difference between the input and output ac voltage signals of a common-emitter amplifier is __________. |
| A. | 0º |
| B. | 90º |
| C. | 180º |
| D. | 360º |
| Answer» D. 360¬∫ | |
| 237. |
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 |
| Answer» C. no current gain | |
| 238. |
If VCC = +18 V, voltage-divider resistor R1 is 4.7 k, and R2 is 1500, what is the base bias voltage? |
| A. | 8.70 V |
| B. | 4.35 V |
| C. | 2.90 V |
| D. | 0.7 V |
| Answer» C. 2.90 V | |
| 239. |
Which is beta's current ratio? |
| A. | IC/IB |
| B. | IC/IE |
| C. | IB/IE |
| D. | IE/IB |
| Answer» B. IC/IE | |
| 240. |
Current gain in a transistor is inversely proportional to collector current. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» C. 1 | |
| 241. |
When a silicon diode is forward biased, what is VBE for a C-E configuration? |
| A. | voltage-divider bias |
| B. | 0.4 V |
| C. | 0.7 V |
| D. | emitter voltage |
| Answer» D. emitter voltage | |
| 242. |
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 |
| Answer» E. | |
| 243. |
The voltage measured from the collector to the emitter is the sum of the voltage base-emitter plus the voltage collector-base. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 244. |
Which is the higher gain provided by a C-E configuration? |
| A. | voltage |
| B. | current |
| C. | resistance |
| D. | power |
| Answer» E. | |
| 245. |
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 |
| Answer» E. | |
| 246. |
The ends of a load line drawn on a family of curves determine: |
| A. | saturation and cutoff |
| B. | the operating point |
| C. | the power curve |
| D. | the amplification factor |
| Answer» B. the operating point | |
| 247. |
The input resistance, Rin of a common-collector amplifier, consists of ____________. |
| A. | Rin = RE √ó AC Current Gain |
| B. | |
| C. | Rin = RE √ó |
| Answer» B. | |
| 248. |
BJTs are "junction" transistors because they use current-carrying P-N junctions. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 249. |
The input resistance of the base of an emitter-follower is usually _________. |
| A. | very low |
| B. | very high |
| C. | shorted to ground |
| D. | open |
| Answer» C. shorted to ground | |
| 250. |
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 |
| Answer» C. collector current (IC) versus collector-emitter voltage (VC) with (VBB) base bias voltage held constant | |