MCQOPTIONS
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MCQOPTIONS
This section includes 521 Mcqs, each offering curated multiple-choice questions to sharpen your Physical Electronics Devices and ICs knowledge and support exam preparation. Choose a topic below to get started.
| 201. |
In the circuit shown V |
| A. | 4.6 V and 1.98 mA |
| B. | 3.18 V and 2.5 mA |
| C. | 5.4 V and 1.56 mA |
| D. | 4.2 V and 2.1 mA |
| Answer» B. 3.18 V and 2.5 mA | |
| 202. |
Among the three configuration the lowest input impedance is obtained by |
| A. | CE |
| B. | CC |
| C. | CB |
| D. | both CB and CC |
| Answer» D. both CB and CC | |
| 203. |
Regarding CC amplifier consider the statements 1 to 4 |
| A. | 1, 2, 4 |
| B. | 1, 3 |
| C. | 2, 4 |
| D. | 3, 4 |
| Answer» C. 2, 4 | |
| 204. |
Among the three configurations the highest output impedance is obtained by |
| A. | CE |
| B. | CC |
| C. | CB |
| D. | CE and CB |
| Answer» D. CE and CB | |
| 205. |
In an emitter follwer with R |
| A. | 25 and 250 K |
| B. | 80 and 800 K |
| C. | 99 and 900 K |
| D. | 100 and 100 K |
| Answer» C. 99 and 900 K | |
| 206. |
A source follower (using an FET) usually has a voltage gain which is |
| A. | Greater than +100 |
| B. | Slightly less than unity but positive |
| C. | Exactly unity but negative |
| D. | About 10 |
| Answer» C. Exactly unity but negative | |
| 207. |
An amplifier without feedback has a gain of 1000. The gain with a negative feedback of 0.009 is |
| A. | 100 |
| B. | 10 |
| C. | 900 |
| D. | 125 |
| Answer» B. 10 | |
| 208. |
The transistor in the amplifier shown has following parameters: h |
| A. | 20 k |
| B. | 16 k |
| C. | 5 k |
| D. | 4 k |
| Answer» B. 16 k | |
| 209. |
The quiescent collector current I |
| A. | Not be affected |
| B. | Decrease |
| C. | Increase |
| D. | Increase or decrease depending on bias stability |
| Answer» D. Increase or decrease depending on bias stability | |
| 210. |
The parameters of an FET are g |
| A. | 333 ohm |
| B. | 3 k ohm |
| C. | 27 k ohm |
| D. | 300 ohm |
| Answer» E. | |
| 211. |
Of the four biasing circuits shown in figure for a BJT, indicate the one which can have maximum bias stability |
| A. | <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/114A.png%20"> |
| B. | <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/114B.png%20"> |
| C. | <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/114c.png%20"> |
| D. | <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/114d.png"> |
| Answer» B. <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/114B.png%20"> | |
| 212. |
For good stabilised biasing of the transistor for the CE amplifier of figure we should have |
| A. | <table><tr><td rowspan="2"> </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>R<sub>E</sub></center></td><td rowspan="2"><< 1</td></tr><td align="center">R<sub>B</sub></td></table> |
| B. | <table><tr><td rowspan="2"> </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>R<sub>E</sub></center></td><td rowspan="2">>> 1</td></tr><td align="center">R<sub>B</sub></td></table> |
| C. | <table><tr><td rowspan="2"> </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>R<sub>B</sub></center></td><td rowspan="2"><< h<sub>FE</sub></td></tr><td align="center">R<sub>E</sub></td></table> |
| D. | >> h |
| E. | <sub>FE</sub> |
| Answer» C. <table><tr><td rowspan="2"> </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>R<sub>B</sub></center></td><td rowspan="2"><< h<sub>FE</sub></td></tr><td align="center">R<sub>E</sub></td></table> | |
| 213. |
The light-emitting diode (LED) |
| A. | Is usually made from silicon |
| B. | Uses a reverse-bised junction |
| C. | Given a light output which increases in temperature |
| D. | Depends on the recombination of holes and electrons |
| Answer» E. | |
| 214. |
When a positive voltage signal is applied to the base of a normally biased NPN common-emitter transistor amplifier |
| A. | The emitter current decreases |
| B. | The collector voltage becomes less positive |
| C. | The base current decreases |
| D. | The collector current decreases |
| Answer» C. The base current decreases | |
| 215. |
If the transistors in figure have high values of and a V |
| A. | 1 mA |
| B. | 3.33 mA |
| C. | 0 |
| D. | 5 mA |
| Answer» B. 3.33 mA | |
| 216. |
Which of the following statement are correct for basic transistor amplifier configuration? |
| A. | CB amplifier has low input impedance and a current gain. |
| B. | CC amplifier has low output impedance and a high current gain. |
| C. | CE amplifier has very poor voltage gain but very high input impedance. |
| D. | The current gain of CB amplifier is higher than the current gain of CC amplifier. |
| E. | Both A and B |
| Answer» F. | |
| 217. |
A zener diode |
| A. | Has a high forward-voltage rating |
| B. | Has a sharp breakdown at low reverse voltage |
| C. | Is useful as an amplifier |
| D. | Has a negative resistance |
| Answer» C. Is useful as an amplifier | |
| 218. |
In a Schmitt trigger using OP amplifiers the output is limited by diode clipper to V |
| A. | 1 and 3 |
| B. | 2 and 3 |
| C. | 1 and 4 |
| D. | None of these statements |
| Answer» D. None of these statements | |
| 219. |
Given for an FET, g |
| A. | 100 kHz |
| B. | 630 kHz |
| C. | 3 MHz |
| D. | 19 MHz |
| Answer» B. 630 kHz | |
| 220. |
A JEFT is set up as a source follower. Given = 200, r |
| A. | 1000 ohm |
| B. | 500 ohm |
| C. | 333 ohm |
| D. | 666 ohm |
| Answer» D. 666 ohm | |
| 221. |
Compared to the junction transistor, FET: |
| A. | 1 and 3 |
| B. | 1 and 2 |
| C. | 2 and 4 |
| D. | 3 and 4 |
| Answer» D. 3 and 4 | |
| 222. |
The 6 V zener diode shown in figure has zero zener resistance and a knee current of 5 mA. The minimum value of R so that voltage across it does not fall below 6 V is |
| A. | 1.2 k |
| B. | 80 |
| C. | 50 |
| D. | 0 |
| Answer» C. 50 | |
| 223. |
A germanium atom contains |
| A. | Four protons |
| B. | Only two electron orbits |
| C. | Four valence electrons |
| D. | Five valence electrons |
| Answer» D. Five valence electrons | |
| 224. |
When atom are held together by the sharing of valence electrons |
| A. | They form a covalent bond |
| B. | The valence electrons are free to move away from the atom |
| C. | Each atom becomes free to move |
| D. | Each shared electron leaves a hole |
| Answer» B. The valence electrons are free to move away from the atom | |
| 225. |
In a half-wave rectifier, the peak value of the ac voltage across the secondary of the transformer is 20 V. If no filter circuit is used, the maximum dc voltage across the load will be |
| A. | 28.28 V |
| B. | 20 V |
| C. | 14.14 V |
| D. | 9 V |
| Answer» D. 9 V | |
| 226. |
In a full-wave rectifier, the current in each of the diodes flows for |
| A. | The complete cycle of the input signal |
| B. | Half cycle of the input signal |
| C. | Less than half cycle of the input signal |
| D. | Zero time |
| Answer» B. Half cycle of the input signal | |
| 227. |
Given that C |
| A. | 0.8 F |
| B. | 0.2 F |
| C. | 1.6 F |
| D. | 3.2 F |
| Answer» E. | |
| 228. |
A CE amplifier has R |
| A. | 500 |
| B. | 400 |
| C. | 50 |
| D. | 40 |
| Answer» C. 50 | |
| 229. |
In regard to the charge control model |
| A. | The relation is I, Q and is similar to V and I in the VI model |
| B. | The Q, I relation is linear |
| C. | Relates majority carriers and their life-time |
| D. | The Q and I have an exponential relation |
| Answer» C. Relates majority carriers and their life-time | |
| 230. |
The cut-in voltage V |
| A. | The same as the barrier potential |
| B. | The same for germanium and silicon |
| C. | The forward voltage below which the current is very small |
| D. | In the region of reverse bias |
| Answer» D. In the region of reverse bias | |
| 231. |
The depletion or space-charge region in a junction diode contains charges that are |
| A. | Mostly majority carriers |
| B. | Mostly minority carriers |
| C. | Mobile donor and acceptor ions |
| D. | FIxed donor and acceptor ions |
| Answer» E. | |
| 232. |
A junction transistor with = 49 and I |
| A. | 441 |
| B. | 490 |
| C. | 539 |
| D. | 540 |
| Answer» E. | |
| 233. |
The base width in a junction transistor is deliberately chosen small so that |
| A. | The electric field is large |
| B. | The concentration gradient of injected carrier increases |
| C. | To reduce recombination of injected minority carriers |
| D. | The majority carriers easily reach the collector |
| Answer» D. The majority carriers easily reach the collector | |
| 234. |
In a p-n-p transistor biased to operate in the active region, the current in the base region consists of |
| A. | Only holes |
| B. | Only electrons |
| C. | Predominantly holes |
| D. | Predominantly electrons |
| Answer» D. Predominantly electrons | |
| 235. |
p-n-p transistor biased the active region of operation. The base current is due to |
| A. | Holes entering the base from the terminal for recombination |
| B. | Holes injected in to the emitter from base |
| C. | Only saturation current due to reverse bias of collector junction |
| D. | Electrons recombining with a part of the holes diffusing in the base region |
| Answer» E. | |
| 236. |
For a given emitter current, the collector current will be higher if |
| A. | The recombination rate in the base region were decreased |
| B. | The emitter region were more lightly doped |
| C. | The minority-carrier mobility in the base region were reduced |
| D. | The base region were made wider |
| Answer» B. The emitter region were more lightly doped | |
| 237. |
The number of minority carriers crossing the junction of a diode depends primarily on the |
| A. | Concentration of doping impurities |
| B. | Magnitude of the potential barrier |
| C. | Magnitude of the forward-bias voltage |
| D. | Rate of thermal generation of electron-hole pairs |
| Answer» E. | |
| 238. |
When we apply reverse bias to a junction diode, it |
| A. | Lowers the potential barrier |
| B. | Raises the potential barrier |
| C. | Greatly increases the minority-carrier current |
| D. | Greatly increases the majority-carrier current |
| Answer» C. Greatly increases the minority-carrier current | |
| 239. |
The forward bias applied to a PN-junction diode is increased from zero to higher values. Rapid increase in the current flow for a relatively, small increase in voltage occurs |
| A. | Immediately |
| B. | Only after the forward bias exceeds the potential barrier |
| C. | When the flow of minority carriers is cause an avalanche breakdown |
| D. | When the depletion area becomes large than the space-charge area |
| Answer» C. When the flow of minority carriers is cause an avalanche breakdown | |
| 240. |
When a pn-junction is biased in the forwad direction |
| A. | Only holes in the p region are injected into the n region |
| B. | Only electrons in the n region are injected into the p region |
| C. | Majority carriers in each region are injected into the other region |
| D. | No carriers move |
| Answer» D. No carriers move | |
| 241. |
Avalanche breakdown in a semiconductor diode occurs when |
| A. | Forward current exceeds a certain value |
| B. | Reverse bias exceeds a certain value |
| C. | Forward bias exceeds a certain value |
| D. | The potential barrier is reduced to zero |
| Answer» C. Forward bias exceeds a certain value | |
| 242. |
In a p-n-p transistor biased in the active region, the dominant carrier flow is |
| A. | Excess holes drifting in the base region |
| B. | Minority carriers electrons injected from base to emitter |
| C. | Minority carriers diffusing in the emitter region |
| D. | Due to concentration gradient of holes, holes diffusing in the base region |
| Answer» E. | |
| 243. |
Tunnel diodes |
| A. | Are mainly operated with reverse bias |
| B. | Have a negative resistance region with reverse bias |
| C. | Has very high impurity concentration thus increasing the barrier width |
| D. | Electrons have a finite probability of penetrating the potential barrier |
| Answer» E. | |
| 244. |
In voltage reference diodes |
| A. | The breakdown mechanism is only due to zener effect |
| B. | For low voltages and heavily doped material the breakdown is due to avalanche multiplication |
| C. | For a limiting reverse voltage which can be used as reference, the reverse current increases depending on the circuit connected |
| D. | The current flow at the reference voltage is due to minority carrier injection |
| Answer» D. The current flow at the reference voltage is due to minority carrier injection | |
| 245. |
In switching a junction diode from forward to reverse bias, the transition interval is the period from the time |
| A. | The diode voltage begins to reverse to the time when the diode has nominally recovered |
| B. | When the diode is forward biased to the time when it is reverse biased |
| C. | Of forward bias to the time diode voltage has attained zero value |
| D. | None of these |
| Answer» B. When the diode is forward biased to the time when it is reverse biased | |
| 246. |
In switching a junction diode from forward to reverse voltage bias, the recovery of the current to the saturation value is delayed. During this time |
| A. | The current is in the same direction as the forward current |
| B. | The excess minority carriers have to drop to zero |
| C. | The excess minority carriers have disappeared and the minority carrier density reaches zero value at the junction |
| D. | The voltage across the diode is in the direction of forward bias |
| Answer» D. The voltage across the diode is in the direction of forward bias | |
| 247. |
In a semiconductor diode, the barrier potential offers opposition to only |
| A. | Majority carriers in both regions |
| B. | Minority carries in both regions |
| C. | FRee electrons in the N region |
| D. | Holes in the P region |
| Answer» B. Minority carries in both regions | |
| 248. |
The circuit in figure shows a zener-regulated d.c. power supply. The zener diode voltage is 15 V. The minimum value of R |
| A. | 27 ohm |
| B. | 45 ohm |
| C. | 15 ohm |
| D. | 24 ohm |
| Answer» C. 15 ohm | |
| 249. |
Given the h parameters for common emitter h |
| A. | 1000 ohms, 40 k ohms |
| B. | 20 ohms, 800 ohms |
| C. | 50 k ohms 40 k ohms |
| D. | 20 ohms and 2 M ohms |
| Answer» E. | |
| 250. |
In a PN-junction diode, if the junction current is zero, this means that |
| A. | The potential barrier has disappeared |
| B. | There are no carriers crossing the junction |
| C. | The number of majority carriers crossing the junction equals the number of minority carriers crossing the junction |
| D. | The number of holes diffusing from the P region equals the number of electrons diffusing from the N region |
| Answer» D. The number of holes diffusing from the P region equals the number of electrons diffusing from the N region | |