MCQOPTIONS
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MCQOPTIONS
This section includes 869 Mcqs, each offering curated multiple-choice questions to sharpen your BITSAT knowledge and support exam preparation. Choose a topic below to get started.
| 301. |
Photoelectric effect occurs only in semiconductors and not in metals. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 302. |
A silicon diode is forward biased and total applied voltage is 5 V. The voltage across p-n junction is |
| A. | 5 V |
| B. | Slightly less than 5 V |
| C. | 0.7 V |
| D. | 0 |
| Answer» D. 0 | |
| 303. |
The forbidden energy gap in semiconductors |
| A. | is always zero |
| B. | lies just below the valence band |
| C. | lies between the valence band and the conduction band |
| D. | lies just above the conduction band |
| Answer» D. lies just above the conduction band | |
| 304. |
At any point on the v-i characteristics of a semiconductor diode, the slope of v-i characteristics is called |
| A. | resistance of diode |
| B. | conductance of diode |
| C. | incremental resistance of diode |
| D. | incremental conductance of diode |
| Answer» E. | |
| 305. |
Which of the following is anti-ferromagnetic material? |
| A. | CrSb |
| B. | NIO |
| C. | MnO |
| D. | All of the above |
| Answer» E. | |
| 306. |
If the temperature of on extrinsic semiconductor is increased so that the intrinsic carrier concentration is doubled, then |
| A. | the majority carrier density doubles |
| B. | the minority carrier density doubles |
| C. | the minority carrier density becomes 4 times the original value |
| D. | both majority and minority carrier densities double |
| Answer» E. | |
| 307. |
Choose the correct match for input resistance of various amplifier configurations shown below configuration.CB : Common Base LO : LowCC : Common Collector MO : moderateCE : Common Emitter HI: High |
| A. | CB-LO, CC-MO, CE-HI |
| B. | CB-LO, CC-HI, CE-MO |
| C. | CB-MO, CC-HI, CE-LO |
| D. | CB-HI, CC-LO, CE-MO |
| Answer» C. CB-MO, CC-HI, CE-LO | |
| 308. |
Hall's effect can be used to measure |
| A. | magnetic field intensity |
| B. | average number of holes |
| C. | carriers concentration |
| D. | electrostatic field intensity |
| Answer» B. average number of holes | |
| 309. |
Assertion (A): Hall effect is used to find the type of semiconductor.Reason (R): When a specimen of semiconductor carrying current I lies in a magnetic field the force on electrons and holes is in opposite directions. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 310. |
When a diode is not conducting, its bias is |
| A. | forward |
| B. | zero |
| C. | reverse |
| D. | zero or reverse |
| Answer» E. | |
| 311. |
An increase in temperature increases the width of depletion layer. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 312. |
Barkhausen criterion of oscillation is |
| A. | Aβ > 1 |
| B. | Aβ = 1 |
| C. | Aβ = < 1 |
| D. | Aβ ≤ 1 |
| Answer» C. Aβ = < 1 | |
| 313. |
When electronic emission occurs due to bombardment of high velocity electrons on a metal surface, it is called secondary emission. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 314. |
An n type silicon bar 0.1 cm long and 100 μm² in cross-sectional area has a majority carrier concentration of 5 x 10²ᴼ/m³ and the carrier mobility is 0.13 mᴼ/V-s at 300k. If the charge of an electron is 1.6 x 10¯¹⁹ coulomb, then the resistance of the bar is |
| A. | 10⁶ ohm |
| B. | 10⁴ ohm |
| C. | 10¯¹ ohm |
| D. | 10¯⁴ ohm |
| Answer» D. 10¯⁴ ohm | |
| 315. |
Which rectifier has the best ratio of rectification? |
| A. | Half wave rectifier |
| B. | Full wave rectifier |
| C. | Bridge rectifier |
| D. | Three phase full wave rectifier |
| Answer» E. | |
| 316. |
Operating point signifies that |
| A. | zero signal IC and VBE |
| B. | zero signal IC and VCE |
| C. | zero signal IB and VCE |
| D. | zero signal IC, VCE |
| Answer» C. zero signal IB and VCE | |
| 317. |
The forbidden energy gap between the valence band and conduction band will be least in case of |
| A. | metals |
| B. | semiconductors |
| C. | insulators |
| D. | all of the above |
| Answer» B. semiconductors | |
| 318. |
Wiedemann-Franz law correlates |
| A. | electrical and thermal conductivities |
| B. | electron arrangement in shells |
| C. | temperature and photo electric emission |
| D. | all of the above |
| Answer» B. electron arrangement in shells | |
| 319. |
Which of the following is basically a voltage controlled capacitance? |
| A. | Zener diode |
| B. | Diode |
| C. | Varactor diode |
| D. | LED |
| Answer» D. LED | |
| 320. |
The on voltage and forward breakover voltage of an SCR depend on |
| A. | gate current alone |
| B. | band gap of semiconductor alone |
| C. | gate current and semiconductor band gap respectively |
| D. | semiconductor band gap and gate current respectively |
| Answer» E. | |
| 321. |
Which of the following statement about the photo electric emission is incorrect? |
| A. | The maximum velocity of emission varies with the frequency of incident light |
| B. | The maximum velocity of emission varies with the intensity of light |
| C. | The amount of photoelectric emission is directly proportional to the intensity of light |
| D. | The quantum yield depends on the frequency and not the intensity of incident light |
| Answer» C. The amount of photoelectric emission is directly proportional to the intensity of light | |
| 322. |
Assertion (A): A high junction temperature may destroy a diode.Reason (R): As temperature increases the reverse saturation current increases. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 323. |
When a normal atom loses an electron |
| A. | the atom loses one-proton simultaneously |
| B. | rest of the electrons move faster |
| C. | the atom becomes a positive ion |
| D. | the atom becomes a negative ion |
| Answer» D. the atom becomes a negative ion | |
| 324. |
The presence of some holes in an intrinsic semiconductor at room temperature is due to |
| A. | valence electrons |
| B. | doping |
| C. | free electrons |
| D. | thermal energy |
| Answer» E. | |
| 325. |
A JFET |
| A. | is current controlled device |
| B. | has low input resistance |
| C. | has high gate current |
| D. | is a voltage controlled device |
| Answer» E. | |
| 326. |
Transconductance characteristics of JFET depict the relation between |
| A. | ID and VGS for different value of VDS |
| B. | ID and VDS for different value of VGS |
| C. | VGS and VDS for different values of ID |
| D. | VDS and ID for different values of VGS |
| Answer» B. ID and VDS for different value of VGS | |
| 327. |
The work function of a photo surface whose threshold wave length is 1200 A, will be |
| A. | 0.103 eV |
| B. | 0.673 eV |
| C. | 1.03 eV |
| D. | 1.27 eV |
| Answer» D. 1.27 eV | |
| 328. |
Pentavalent impurity creates n type semiconductor. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 329. |
The permeability of soft iron can be increased by |
| A. | purifying it |
| B. | reducing carbon percentage |
| C. | alloying with cobalt |
| D. | increasing percentage |
| Answer» D. increasing percentage | |
| 330. |
Which of these is also called 'hot carrier diode'? |
| A. | PIN diode |
| B. | LED |
| C. | Photo diode |
| D. | Schottky diode |
| Answer» E. | |
| 331. |
When a substance is repelled by a magnetic field it is known as |
| A. | ferromagnetic |
| B. | antiferromagnetic |
| C. | diamagnetic |
| D. | paramagnetic |
| Answer» D. paramagnetic | |
| 332. |
Assertion (A): Power transistors are more commonly of silicon npn type.Reason (R): The fabrication of silicon npn transistors is easy. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 333. |
All of the following elements have three valence electrons EXCEPT |
| A. | boron |
| B. | indium |
| C. | gallium |
| D. | arsenic |
| Answer» E. | |
| 334. |
The number of p-n junctions in a semiconductor diode are |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 1 or 2 |
| Answer» C. 2 | |
| 335. |
The units for transconductance are |
| A. | ohms |
| B. | amperes |
| C. | volts |
| D. | siemens |
| Answer» E. | |
| 336. |
Ohmic range of carbon composition resistors is |
| A. | 10 to 100 ohms |
| B. | 10 to 10 K ohms |
| C. | 10 to 200 ohms |
| D. | 10 to 25 M ohms |
| Answer» E. | |
| 337. |
The unit of thermal resistance of a semi-conductor device is |
| A. | Ohms |
| B. | Ohms/°C |
| C. | °C/ohm |
| D. | °C/watt |
| Answer» E. | |
| 338. |
Light dependent resistor is |
| A. | photo resistive device |
| B. | photo voltaic device |
| C. | photo emissive device |
| D. | either (a) or (c) |
| Answer» B. photo voltaic device | |
| 339. |
Which of these has a layer of intrinsic semiconductor? |
| A. | Zener diode |
| B. | PIN diode |
| C. | Photo diode |
| D. | Schottky diode |
| Answer» C. Photo diode | |
| 340. |
Addition of 0.3 to 3.5% silicon to iron |
| A. | increases the electrical resistivity of iron |
| B. | decreases the electrical resistivity of iron |
| C. | does not change electrical resistivity of iron |
| D. | silicon can't be added with iron |
| Answer» B. decreases the electrical resistivity of iron | |
| 341. |
For an P-N-P transistor in normal operation its junction are biased as |
| A. | emitter base : reverse, collector base : forward |
| B. | emitter base : forward, collector base : reverse |
| C. | emitter base : forward, collector base : forward |
| D. | emitter base : reverse, collector base : reverse |
| Answer» C. emitter base : forward, collector base : forward | |
| 342. |
n-type semiconductors |
| A. | are negatively charged |
| B. | are produced when indium is added as impurity to germanium |
| C. | are produced when phosphorus is added as impurity to silicon |
| D. | none of the above |
| Answer» D. none of the above | |
| 343. |
Which of these is used in seven segment display? |
| A. | PIN diode |
| B. | LED |
| C. | Photo diode |
| D. | Tunnel diode |
| Answer» C. Photo diode | |
| 344. |
When avalanche breakdown occurs covalent bonds are not affected. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 345. |
The density of states (i.e. number of states per eV per m³) in the conduction band for energy level E is proportional to |
| A. | √E |
| B. | E |
| C. | E^(1.5) |
| D. | E² |
| Answer» B. E | |
| 346. |
For an P-channel enhancement type MOSFET determine the drain current if K = 0.278 x 10¯³A/V², VGS = -4V, VT = -2V, Voltage equivalent at 27°C = 26 mV. |
| A. | 10 mA |
| B. | 1.11 mA |
| C. | 0.751 mA |
| D. | 46.98 mA |
| Answer» C. 0.751 mA | |
| 347. |
The impurity commonly used for realizing the base region of a n-p-n transistor is |
| A. | gallium |
| B. | indium |
| C. | boron |
| D. | phosphorus |
| Answer» D. phosphorus | |
| 348. |
Consider the following statements.The functions of an oxide layer in an IC device is to 1. mask against diffusion or ion implant2. insulate the surface electrically3. increase the melting point of silicon4. produce a chemically stable protective layer Of these statements, which are true. |
| A. | 1, 2, 3 |
| B. | 1, 3, 4 |
| C. | 2, 3, 4 |
| D. | 1, 2, 4 |
| Answer» E. | |
| 349. |
In which of the following does a negative resistance region exist in the v-i characteristics? |
| A. | PIN diode |
| B. | Schottky diode |
| C. | Tunnel diode |
| D. | Zener diode |
| Answer» D. Zener diode | |
| 350. |
On which of the following effect do thermocouples work? |
| A. | Thomson effect |
| B. | Seeback effect |
| C. | Peltier effect |
| D. | Joule effect |
| Answer» C. Peltier effect | |