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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.
| 801. |
In a piezoelectric crystal, applications of a mechanical stress would produce |
| A. | plastic deformation of the crystal |
| B. | magnetic dipoles in the crystal |
| C. | electrical polarization in the crystal |
| D. | shift in the Fermi level |
| Answer» D. shift in the Fermi level | |
| 802. |
If μn is mobility of free electron and μp is mobility of holes then for silicon at 300 K |
| A. | μn = μp |
| B. | μn > μp |
| C. | μn < μp |
| D. | μn may be more or less than μp |
| Answer» C. μn < μp | |
| 803. |
If both emitter base and collector base junctions of a BJT are forward biased, the transistor is in |
| A. | active region |
| B. | saturated region |
| C. | cut off region |
| D. | inverse mode |
| Answer» C. cut off region | |
| 804. |
In the schematic representation of bipolar junction transistor, the direction of arrow shows the direction of flow of |
| A. | holes |
| B. | electrons |
| C. | holes in pnp and electrons in npn |
| D. | electrons in pnp and holes in npn |
| Answer» B. electrons | |
| 805. |
The voltage at which Avalanche occurs is known as |
| A. | cut in voltage |
| B. | barrier voltage |
| C. | breakdown voltage |
| D. | depletion voltage |
| Answer» D. depletion voltage | |
| 806. |
The current due to thermionic emission is given by Richardson Dushman equation. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 807. |
If E is energy level of electron and EF is fermi level, and T = 0 and E > EF, then |
| A. | the probability of finding an occupied quantum state of energy higher than EF is zero |
| B. | all quantum states with energies greater than EF are occupied |
| C. | some quantum states with energies greater than EF are occupied |
| D. | majority of quantum states with energies greater than EF are occupied |
| Answer» B. all quantum states with energies greater than EF are occupied | |
| 808. |
Crossover distortion behaviour is characteristic of |
| A. | class A O/P stage |
| B. | class B O/P stage |
| C. | class AB output stage |
| D. | common pulse O/P state |
| Answer» C. class AB output stage | |
| 809. |
For an n-channel JEFT having drain source voltage constant if the gate source voltage is increased (more negative) pinch off would occur for |
| A. | high values of drain current |
| B. | saturation values of drain current |
| C. | zero drain current |
| D. | gate current equal to the drain current |
| Answer» D. gate current equal to the drain current | |
| 810. |
Assertion (A): A JFET behaves as a resistor when VGS < VP.Reason (R): When VGS < VP, the drain current in a JFET is almost constant. |
| 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» D. A is false but R is true | |
| 811. |
Which of the following is known as insulated gate FET? |
| A. | JFET |
| B. | MOSFET |
| C. | Both JFET and MOSFET |
| D. | None of the above |
| Answer» C. Both JFET and MOSFET | |
| 812. |
- ve feedback in an amplifier |
| A. | reduces gain |
| B. | increase frequency and phase distortion |
| C. | reduce bandwidth |
| D. | increase noise |
| Answer» B. increase frequency and phase distortion | |
| 813. |
The conduction band is |
| A. | same as forbidden energy gap |
| B. | generally located on the top of the crystal |
| C. | generally located on the bottom of the crystal |
| D. | a range of energies corresponding to the energies of the free electrons |
| Answer» E. | |
| 814. |
If E (i.e., available energy state) = EF(i.e., Fermi level), then probability that state E will be occupied is 0.5 for any temperature T. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 815. |
In active filter circuits, inductances are avoided mainly because they |
| A. | are always associated with some resistance |
| B. | are bulky and unsuitable for miniaturisation |
| C. | are non-linear in nature |
| D. | saturate quickly |
| Answer» C. are non-linear in nature | |
| 816. |
The process of deliberately adding impurity to a semi-conductor material is called |
| A. | impurification |
| B. | pollution |
| C. | deionisation |
| D. | doping |
| Answer» E. | |
| 817. |
How many free electrons does a p type semiconductor has? |
| A. | only those produced by thermal energy |
| B. | only those produced by doping |
| C. | those produced by doping as well as thermal energy |
| D. | any of the above |
| Answer» B. only those produced by doping | |
| 818. |
Two identical silicon diodes D1 and D2 are connected back to back shown in figure. The reverse saturation current Is of each diode is 10-8 amps and the breakdown voltage VBr is 50 v. Evaluate the voltages VD1 and VD2 dropped across the diodes D1 and D2 assuming KT/q to be 25 m V. |
| A. | 4.983 V, 0.017 V |
| B. | - 4.98 V, - 0.017 V |
| C. | 0.17 V, 4.983 V |
| D. | - 0.017 V, - 4.98 V |
| Answer» C. 0.17 V, 4.983 V | |
| 819. |
The depletion layer in a reverse biased p-n junction is due to the presence of |
| A. | electrons |
| B. | holes |
| C. | both electrons and holes |
| D. | immobile ions |
| Answer» E. | |
| 820. |
In a common emitter BJT amplifier, the maximum usable supply voltage is limited by |
| A. | avalanche Beakdown of Base-Emitter junction |
| B. | collector emitter breakdown voltage with base open(βVCEO) |
| C. | collector emitter breakdown voltage with emitter open(βVCEO) |
| D. | zener break down voltage of the emitter base junction |
| Answer» D. zener break down voltage of the emitter base junction | |
| 821. |
Intrinsic concentration of charge carriers in a semiconductor varies as |
| A. | T |
| B. | T² |
| C. | T³ |
| D. | T¯² |
| Answer» D. T¯² | |
| 822. |
Measurement of Hall coefficient enables the determination of |
| A. | recovery time of stored carrier |
| B. | type of conductivity and concentration of charge carriers |
| C. | temperature coefficient and thermal conductivity |
| D. | Fermi level and forbidden energy gap |
| Answer» C. temperature coefficient and thermal conductivity | |
| 823. |
An amplifier without feedback has a voltage gain of 50, input resistance of 1 kΩ and output resistance of 2.5 kΩ. The input resistance of the current shunt -ve feedback amplifier using the above amplifier with a feedback factor of 0.2 is |
| A. | 1/11 kΩ |
| B. | 1/5 kΩ |
| C. | 5 kW |
| D. | 11 kW |
| Answer» B. 1/5 kΩ | |
| 824. |
A semiconductor in its purest form called |
| A. | intrinsic semiconductor |
| B. | extrinsic semiconductor |
| C. | P-type semiconductor |
| D. | N-type semiconductor |
| Answer» B. extrinsic semiconductor | |
| 825. |
Conductivity σ, mobility μ and Hall coefficient KH are related as |
| A. | μ = σKH |
| B. | σ = μKH |
| C. | KH = μσ |
| D. | KH =(μσ)^1.1 |
| Answer» B. σ = μKH | |
| 826. |
The rate of change of excess carrier density is proportional to carrier density. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 827. |
The charge of an electron is |
| A. | 1.6 x 10¯¹⁷ coulomb |
| B. | 1.6 x 10¯¹⁹ coulomb |
| C. | 1.6 x 10¯²¹ coulomb |
| D. | 1.6 x 10¯²³ coulomb |
| Answer» C. 1.6 x 10¯²¹ coulomb | |
| 828. |
A Darlington emitter follower circuit is some times used in the output stage of a TTL gate in order to |
| A. | increase its IQL |
| B. | reduce its I0H |
| C. | increase its speed of operation |
| D. | reduce power dissipation |
| Answer» D. reduce power dissipation | |
| 829. |
A particular green LED emits light of wavelength 5490, Å, the energy bandgap of the semiconductor material used there is .. h = 6.6 x 10-34 J sec. |
| A. | 2.26 eV |
| B. | 1.98 eV |
| C. | 1.17 eV |
| D. | 0.74 eV |
| Answer» B. 1.98 eV | |
| 830. |
If the energy gap of a semiconductor is 1.1 eV, then it would be |
| A. | opaque to visible light |
| B. | transparent to visible light |
| C. | transparent to ultraviolet radiation |
| D. | transparent to infrared radiation |
| Answer» B. transparent to visible light | |
| 831. |
The behaviour of a JFET is similar to that of |
| A. | NPN transistor |
| B. | PNP transistor |
| C. | SCR |
| D. | Vacuum triode |
| Answer» E. | |
| 832. |
With an ac input from 50 Hz power line, the ripple frequency is |
| A. | 50 Hz in the dc output of half wave as well as full wave rectifier |
| B. | 100 Hz in the dc output of half wave as well as full wave rectifier |
| C. | 50 Hz in the dc output of half wave and 100 Hz in the dc output of full wave |
| D. | 100 Hz in the dc output of half wave and 50 Hz in the dc output of full wave |
| Answer» D. 100 Hz in the dc output of half wave and 50 Hz in the dc output of full wave | |
| 833. |
For a BJT, avalanche multiplication factor depends on |
| A. | VCE |
| B. | VCB |
| C. | VBE |
| D. | none |
| Answer» C. VBE | |
| 834. |
Figure represents a |
| A. | Tunnel diode |
| B. | Zener diode |
| C. | Photo diode |
| D. | Photo sensitive diode |
| Answer» C. Photo diode | |
| 835. |
Diffusion constants Dp, Dn mobility μp, μn and absolute temperature T are related as |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 836. |
If an additional two diodes were used to connect the 1 kW load across a bridge rectifier circuits, utilizing the full secondary of the transformer, how much d.c. power could be delivered using a transformer with the rating of 105 VA? |
| A. | 35 W |
| B. | 60 W |
| C. | 85 W |
| D. | 100 W |
| Answer» D. 100 W | |
| 837. |
The drain characteristics of JFET are drawn between |
| A. | VGS and VDS for different values of drain current |
| B. | drain current and VGS for different values of VDS |
| C. | drain current and VDS for different values of VGS |
| D. | drain current and VGS for one value of VDS |
| Answer» D. drain current and VGS for one value of VDS | |
| 838. |
As comparated to an ordinary p-n diode, the extent of impurity atoms in a tunnel diode |
| A. | is more |
| B. | is less |
| C. | may be more or less |
| D. | is almost the same |
| Answer» B. is less | |
| 839. |
Consider the following statements: The function of oxide layer in an IC device is to 1. mask against diffusion or non implant2. insulate the surface electrically3. increase the melting point of silicon4. produce a chemically stable protective layer Of these statements: |
| A. | 1, 2, 3 are correct |
| B. | 1, 3, 4 are correct |
| C. | 2, 3, 4 are correct |
| D. | 1, 2, 4 are correct |
| Answer» E. | |
| 840. |
The collector to emitter cutoff current (ICE0) of a transmitter is related to collector to base cut off current (ICB0) as |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 841. |
Consider the following statements 1. An iron cored choke is a nonlinear device.2. A carbon resistor kept in a sunlight is a time - invariant and passive device.3. A dry cell is a time - varying and active device.4. An air capacitor is a time - invariant and passive device Of these statements |
| A. | 1, 2, 3 and 4 are correct |
| B. | 1, 2 and 3 are correct |
| C. | 1, 2 and 4 are correct |
| D. | 2 and 4 are correct |
| Answer» B. 1, 2 and 3 are correct | |
| 842. |
In an n type semiconductor |
| A. | number of free electrons and holes are equal |
| B. | number of free electrons is much greater than the number of holes |
| C. | number of free electrons may be equal or less than the number of holes |
| D. | number of holes is greater than the number of free electrons |
| Answer» C. number of free electrons may be equal or less than the number of holes | |
| 843. |
Figure represents a |
| A. | Diode rectifier |
| B. | Schottky diode |
| C. | Varistor |
| D. | None of the above |
| Answer» C. Varistor | |
| 844. |
Which of the following expressions may be used to correctly describe the temperature (T) variation of the intrinsic carrier density (ni) of a semiconductor? |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 845. |
The V-I characteristic of a semi-conductor diode is shown in figure. From this figure it can be concluded that |
| A. | The diode is a silicon diode |
| B. | The diode is a germanium diode |
| C. | Break down voltage of the diode is 0.7 V |
| D. | At 1 V rated current will pass through the diode |
| Answer» B. The diode is a germanium diode | |
| 846. |
The diode and the moving coil milliammeter of figure are assumed to be ideal. The meter reading is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 847. |
The dipole moment per unit volume as a function of E in the case of an insulator is given by (symbols have the usual meaning). |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 848. |
An electron in the conduction band |
| A. | has higher energy than the electron in the valence band |
| B. | has lower energy than the electron in the valence band |
| C. | loses its charge easily |
| D. | jumps to the top of the crystal |
| Answer» B. has lower energy than the electron in the valence band | |
| 849. |
The magnetization 'm' of a superconductor in a field of H is |
| A. | extremely small |
| B. | - H |
| C. | - 1 |
| D. | Zero |
| Answer» C. - 1 | |
| 850. |
Which of the following could be the maximum current rating of junction diode by 126? |
| A. | 1 A |
| B. | 10 A |
| C. | 20 A |
| D. | 100 A |
| Answer» B. 10 A | |