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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.
| 401. |
Under high electric field, in a semiconductor with increasing electric field |
| A. | The mobility of charge carriers decreases |
| B. | The mobility of charge carriers increases |
| C. | The velocity of charge carriers saturates |
| D. | The velocity of charge carriers increases |
| Answer» D. The velocity of charge carriers increases | |
| 402. |
Ratio of maximum resistivity to intrinsic resistivity max / i is expressed as |
| A. | n + p / 2 p |
| B. | n + p / n p |
| C. | n + p / 2 n p |
| D. | n + p / 2 n |
| Answer» D. n + p / 2 n | |
| 403. |
Match and select the correct answer using codes: List-I |
| A. | 4123 |
| B. | 4321 |
| C. | 2143 |
| D. | 2341 |
| Answer» B. 4321 | |
| 404. |
Assuming the forward diode drop as 0V, the output voltage V |
| A. | 0V |
| B. | 5V |
| C. | 3 5V |
| D. | 6 5V |
| Answer» D. 6 5V | |
| 405. |
Which of the following is not associated with a pn junction? |
| A. | Junction capacitance |
| B. | Charge storage capacitance |
| C. | Depletion capacitance |
| D. | Channel length modulation |
| Answer» E. | |
| 406. |
The peak current through the resistor of circuit of figure, assuming the diodes to be ideal, is |
| A. | 12 mA |
| B. | 4 mA |
| C. | 16 mA |
| D. | 8 mA |
| Answer» E. | |
| 407. |
A p-n junction has a built-in potential of 0 8 V. The depletion layer width at a reverse bias of 1 2 V is 2 m. For a reverse bias of 7 2 V, the depletion layer width will be |
| A. | 4 m |
| B. | 4 9 m |
| C. | 8 m |
| D. | 12 m |
| Answer» B. 4 9 m | |
| 408. |
In figure, capacitor C is initially charged with voltage V |
| A. | <table><tr><td rowspan="2">0, </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> V<sub>0</sub> </center></td></tr><td align="center">R</td></table> |
| B. | <table><tr><td rowspan="2"> V<sub>0</sub> , </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> V<sub>0</sub> </center></td></tr><td align="center">R</td></table> |
| C. | <table><tr><td rowspan="2">- V<sub>0</sub> - </td> <td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> V<sub>0</sub> </center></td></tr><td align="center">R</td></table> |
| D. | <table><tr><td rowspan="2">V<sub>0</sub> , </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> V<sub>0</sub> </center></td></tr><td align="center">R</td></table> |
| Answer» C. <table><tr><td rowspan="2">- V<sub>0</sub> - </td> <td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> V<sub>0</sub> </center></td></tr><td align="center">R</td></table> | |
| 409. |
In figure, PIV required for the diode is |
| A. | 300 V |
| B. | 100 V |
| C. | 200 V |
| D. | 400 V |
| Answer» E. | |
| 410. |
A voltage V = 4 sin t is applied to the terminals A and B of the circuit shown in figure. The diodes are assumed to be ideal. The impedance offered by the circuit across the terminals A and B in kilo-ohms is |
| A. | 5 |
| B. | 20 |
| C. | 10 |
| D. | None of these |
| Answer» D. None of these | |
| 411. |
In figure, capacitor C is charged to V |
| A. | 15 A, 200 V |
| B. | 20 A, 200 V |
| C. | 25 A, 250 V |
| D. | 15 A, 150 V |
| Answer» B. 20 A, 200 V | |
| 412. |
The ratio of diffusion constant to mobility of carriers |
| A. | Depends on temperature |
| B. | Varies with lifetime |
| C. | Universal constant |
| D. | None of these |
| Answer» B. Varies with lifetime | |
| 413. |
Why is an external pass resistor used in a voltage regulation? |
| A. | For short circuit protection |
| B. | For increasing the current that regulator can handle |
| C. | For increasing the output voltage |
| D. | For improving the regulation |
| Answer» C. For increasing the output voltage | |
| 414. |
The reverse saturation current of a Si-based p-n junction diode increases 32 times due to a rise in ambient temperature. If the original temperature was 40 C, what is the final temperature? |
| A. | 90 C |
| B. | 72 C |
| C. | 45 C |
| D. | 50 C |
| Answer» B. 72 C | |
| 415. |
The change in barrier potential of silicon p-n junction with temperature is |
| A. | 0 025 volts per degree C |
| B. | 0 250 volts per degree C |
| C. | 0 030 volts per degree C |
| D. | 0 014 volts per degree C |
| Answer» B. 0 250 volts per degree C | |
| 416. |
The equivalent circuits of a diode, during forward biased and reverse biased conditions, are shown in the figure. |
| A. | (A) |
| B. | (B) |
| C. | (C) |
| D. | (D) |
| Answer» B. (B) | |
| 417. |
Avalanche breakdown diodes have |
| A. | A positive temperature coefficient |
| B. | A negative temperature coefficient |
| C. | A breakdown voltage is independent of temperature |
| D. | None of these |
| Answer» B. A negative temperature coefficient | |
| 418. |
If the load resistance decreases in a zener regulator, the series current |
| A. | Decreases |
| B. | Increases |
| C. | Stays the same |
| D. | Equals the source voltage divided by the series resistance |
| Answer» D. Equals the source voltage divided by the series resistance | |
| 419. |
Each diode in figure can be described by a cut-in voltage and zero resistance. If the cut-in voltage of diode D1 is 0 2V and of diode D2 is 0 6 V, the magnitude of current i |
| A. | 20 mA, 0 mA |
| B. | 10 mA, 0 mA |
| C. | 15 mA, 0 mA |
| D. | 25 mA, 0 mA |
| Answer» C. 15 mA, 0 mA | |
| 420. |
A 4.7 zener has a resistance of 15 . When a current 20 mA passes through it, then the terminal voltage is |
| A. | 5 V |
| B. | 10 V |
| C. | 15 V |
| D. | 20 V |
| Answer» B. 10 V | |
| 421. |
When a reverse current in a zener diode increases from 20mA to 30 mA, the zener voltage changes from 5.6 V to 5.65 V. The zener resistance is |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 5 |
| Answer» E. | |
| 422. |
A zener diode has a dc power dissipation rating of 500 mW and a zener voltage rating of 7.5 V. The value of IZM is |
| A. | 70 mA |
| B. | 66.67 mA |
| C. | 86.67 mA |
| D. | 76.67 mA |
| Answer» C. 86.67 mA | |
| 423. |
A device having characteristics very close to that of an ideal voltage source is |
| A. | Diode |
| B. | Zener diode |
| C. | Transistor |
| D. | FET |
| Answer» C. Transistor | |
| 424. |
In a voltage multiplier circuit diodes and capacitors are suitable for |
| A. | High voltage high current device |
| B. | High voltage low current device |
| C. | Low voltage low current device |
| D. | Low voltage high current device |
| Answer» C. Low voltage low current device | |
| 425. |
The dynamic impedance of zener diode |
| A. | Increases with increase in current through it |
| B. | Decreases with increase in current through it |
| C. | Is independent of current passing through it |
| D. | None of these |
| Answer» C. Is independent of current passing through it | |
| 426. |
The figure given below shows the transfer characteristics of which one of the following |
| A. | Peak clipper |
| B. | Bottom clipper |
| C. | Clamper |
| D. | Two level clipper |
| Answer» B. Bottom clipper | |
| 427. |
In the given circuit, D |
| A. | 60 mA and 0 V |
| B. | 50 mA and 0 V |
| C. | 53 mA and 0 7 V |
| D. | 44 mA and 1 58 V |
| Answer» B. 50 mA and 0 V | |
| 428. |
Select the correct output (V |
| A. | (A) |
| B. | (B) |
| C. | (C) |
| D. | (D) |
| Answer» E. | |
| 429. |
Assuming an operating temperature T = 300 K and corresponding V |
| A. | 60 mV |
| B. | 120 mV |
| C. | 180 mV |
| D. | 240 mV |
| Answer» C. 180 mV | |
| 430. |
Zener breakdown diodes have |
| A. | A positive temperature coefficient |
| B. | A Negative temperature coefficient |
| C. | A breakdown voltage is independent of temperature |
| D. | None of these |
| Answer» C. A breakdown voltage is independent of temperature | |
| 431. |
The break down that occurs in reverse bias conditions in a wider junction diodes is |
| A. | The zener breakdown |
| B. | The avalanche breakdown |
| C. | Either zener or avalanche breakdown |
| D. | None of these |
| Answer» C. Either zener or avalanche breakdown | |
| 432. |
The breakdown that occurs in reverse bias conditions in a narrow junction diodes is |
| A. | The zener breakdown |
| B. | The avalanche breakdown |
| C. | Either zener or avalanche breakdown |
| D. | None of these |
| Answer» B. The avalanche breakdown | |
| 433. |
In avalanche multiplication |
| A. | Distribution of covalent bond occurs by collision |
| B. | Direct rupture of bonds |
| C. | Both (A) and (B) |
| D. | None of these |
| Answer» B. Direct rupture of bonds | |
| 434. |
An avalanche diode |
| A. | Is the same as the zener diode |
| B. | Is operated in the forward-biased mode only |
| C. | Is usually operated in the reverse biased mode only |
| D. | None of these |
| Answer» D. None of these | |
| 435. |
For the zener diode shown in the figure, the zener voltage at knee is 7V, the knee current is negligible and the zener dynamic resistance is 10 . If the input voltage (V |
| A. | 7 to 7.29 V |
| B. | 7.14 to 7.29 V |
| C. | 7.14 to 7.43 V |
| D. | 7.29 to 7.43 V |
| Answer» D. 7.29 to 7.43 V | |
| 436. |
In a regulated power supply using zener diode the unregulated input voltage as compared to the regulated output voltage must be |
| A. | Equal |
| B. | Smaller |
| C. | Larger |
| D. | Larger with opposite polarity |
| Answer» D. Larger with opposite polarity | |
| 437. |
Match List-I (Diode) with List-II (Applications) and select the correct answer using the code given below the lists |
| A. | 2143 |
| B. | 3142 |
| C. | 3412 |
| D. | 2413 |
| Answer» E. | |
| 438. |
In a forward biased photodiode with increase in incident light intensity, the diode current |
| A. | Increases |
| B. | Remains constant |
| C. | Decreases |
| D. | Remaining constant, the voltage drop across the diode increases |
| Answer» D. Remaining constant, the voltage drop across the diode increases | |
| 439. |
The saturation currents of the two diodes are 1 and 2mA. The breakdown voltages of the diodes are the same and are equal to 100V. The current in the diode D |
| A. | 0 mA |
| B. | 1 mA |
| C. | 2 mA |
| D. | 3 mA |
| Answer» C. 2 mA | |
| 440. |
If the load resistance decreases in a zener regulator, the zener current |
| A. | Decreases |
| B. | Increases |
| C. | Stays the same |
| D. | Equals the source voltage divided by the series resistance |
| Answer» C. Stays the same | |
| 441. |
Group 1 lists four different semiconductor devices. Match each device in Group 1 with its characteristic property in Group 2. |
| A. | P-3, Q-1, R-4, S-2 |
| B. | P-1, Q-4, R-3, S-2 |
| C. | P-3, Q-4, R-1, S-2 |
| D. | P-3, Q-2, R-1, S-4 |
| Answer» D. P-3, Q-2, R-1, S-4 | |
| 442. |
Match List-I with List-II and select the correct answer using the code given below the lists |
| A. | 1234 |
| B. | 3412 |
| C. | 1432 |
| D. | 3214 |
| Answer» B. 3412 | |
| 443. |
Group I lists four types of p-n junction diodes. Match each device in Group 1 with one of the options in Group 2 to indicate the bias condition of that device in its normal mode of operation. |
| A. | P-1, Q-2, R-1, S-2 |
| B. | P-2, Q-1, R-1, S-2 |
| C. | P-2, Q-2, R-2, S-1 |
| D. | P-2, Q-1, R-2, S-2 |
| Answer» C. P-2, Q-2, R-2, S-1 | |
| 444. |
Find the correct match between and Group 2 |
| A. | E-4, F-2, G-1, H-3 |
| B. | E-2, F-4, G-1, H-3 |
| C. | E-3, F-4, G-1, H-2 |
| D. | E-1, F-3, G-2, H-4 |
| Answer» D. E-1, F-3, G-2, H-4 | |
| 445. |
In the following limiter circuit, an input voltage V |
| A. | 6 1 V, 0 7 V |
| B. | 0 7 V, 7 5 V |
| C. | 7 5 V, 0 7 V |
| D. | 7 5 V, 7 5 V |
| Answer» D. 7 5 V, 7 5 V | |
| 446. |
A Zener diode regulator shown in the figure given below is to be designed to meet the following specifications |
| A. | R 1800 |
| B. | 2000 R 2200 |
| C. | 3700 R 4000 |
| D. | R > 4000 |
| Answer» B. 2000 R 2200 | |
| 447. |
Match List-I (Devices) with List-II (Property) and select the correct answer using the code given below the lists |
| A. | 1342 |
| B. | 2431 |
| C. | 1432 |
| D. | 2341 |
| Answer» E. | |
| 448. |
For the Zener diode shown in the figure, the Zener voltage at knee is 7 V, the knee current is negligible and the Zener dynamic resistance is 10 . If the input voltage (V |
| A. | 7 00 to 7 29 V |
| B. | 7 14 to 7 29 V |
| C. | 7 14 to 7 43 V |
| D. | 7 29 to 7 43 V |
| Answer» D. 7 29 to 7 43 V | |
| 449. |
Match List-I (Diode type) with List-II (Important properties) and select the correct answer using the code given below the lists |
| A. | 2431 |
| B. | 1342 |
| C. | 2341 |
| D. | 1432 |
| Answer» D. 1432 | |
| 450. |
A zener diode in the circuit shown in the figure below, has a knee current of 5 mA and a maximum allowed power dissipation of 300 mW. What are the minimum and maximum load currents that can be drawn safely from the circuit, keeping the output voltage V |
| A. | 0 mA, 180 mA |
| B. | 5 mA, 110 mA |
| C. | 10 mA, 55 mA |
| D. | 60 mA, 180 mA |
| Answer» D. 60 mA, 180 mA | |