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.
| 701. |
When a P-N junction is unbiased, the junction current at equilibrium is |
| A. | zero as no charges cross the junction |
| B. | zero as equal number of carriers cross the barrier |
| C. | mainly due to diffusion of majority carriers |
| D. | mainly due to diffusion of minority carriers |
| Answer» C. mainly due to diffusion of majority carriers | |
| 702. |
The voltage across the secondary of the transformer in a half wave rectifier (without any filter circuit) is 25 volts. The maximum voltage on the reverse biased diode will be |
| A. | 100 V |
| B. | 50 V |
| C. | 25 V |
| D. | 12.5 V |
| Answer» D. 12.5 V | |
| 703. |
The band gap of Si at room temperature is |
| A. | 1.3 eV |
| B. | 0.7 eV |
| C. | 1.1 eV |
| D. | 1.4 eV |
| Answer» D. 1.4 eV | |
| 704. |
Assertion (A): FET has characteristics very similar to that of pentode.Reason (R): Both FET and pentode are voltage controlled devices. |
| 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 | |
| 705. |
If for a silicon n-p-n transistor, the base to emitter voltage (VBE) is 0.7 V and the collector to base voltage VCB is 0.2 Volt, then the transistor is operating in the |
| A. | normal active mode |
| B. | saturation mode |
| C. | inverse active mode |
| D. | cut off mode |
| Answer» B. saturation mode | |
| 706. |
Assertion (A): In a BJT, the base region is very thick.Reason (R): In p-n-p transistor most of holes given off by emitter diffuse through the base. |
| 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» E. | |
| 707. |
In p-n-p transistor the current IE has two components viz. IEP due to injection of holes from p-region to n-region and IE due to injection of electrons from n-region to p-region. Then |
| A. | IEp and IEn are almost equal |
| B. | IEp >> IEn |
| C. | IEn >> IEp |
| D. | either (a) or (c) |
| Answer» C. IEn >> IEp | |
| 708. |
Which of the following has highest conductivity? |
| A. | Silver |
| B. | Aluminium |
| C. | Tungsten |
| D. | Platinum |
| Answer» B. Aluminium | |
| 709. |
Which of these has peak and valley points in v-i curve? |
| A. | Tunnel diode |
| B. | Zener diode |
| C. | PIN diode |
| D. | Schottky diode |
| Answer» B. Zener diode | |
| 710. |
n channel FETs are better as compared to p-channel FET because |
| A. | they are more efficient |
| B. | they have high switching time |
| C. | they have higher input impedance |
| D. | mobility of electrons is more than that of holes |
| Answer» E. | |
| 711. |
In an n channel JFET |
| A. | ID, IS and IG are considered positive when flowing into the transistor |
| B. | ID and IS are considered positive when flowing into transistor and IG is considered positive when flowing out of it |
| C. | ID, IS, IG are considered positive when flowing out of transistor |
| D. | IS and IG are considered positive when flowing into transistor and ID is considered positive when flowing out of it |
| Answer» B. ID and IS are considered positive when flowing into transistor and IG is considered positive when flowing out of it | |
| 712. |
Lowest resistivity of the following is |
| A. | constantan |
| B. | german silver |
| C. | manganin |
| D. | nichrome |
| Answer» C. manganin | |
| 713. |
If the reverse voltage across a p-n junction is increased three times, the junction capacitance |
| A. | will decrease |
| B. | will increase |
| C. | will decrease by an approximate factor of about 2 |
| D. | will increase by an approximate factor of about 2 |
| Answer» D. will increase by an approximate factor of about 2 | |
| 714. |
A varactor diode is |
| A. | reverse biased |
| B. | forward biased |
| C. | biased to breakdown |
| D. | unbiased |
| Answer» B. forward biased | |
| 715. |
A sample of N-type semiconductor has electron density of 6.25 x 10¹⁸/cm³ at 300k. If the intrinsic concentration of carriers in this sample is 2.5 x 10¹³/cm³ at this temperature the hole density works out to be |
| A. | 10⁶/cm³ |
| B. | 10⁸/cm³ |
| C. | 10¹ᴼ/cm³ |
| D. | 10¹²/cm³ |
| Answer» C. 10¹ᴼ/cm³ | |
| 716. |
A long specimen of P type semiconductor material |
| A. | is + vely charged |
| B. | is electrically neutral |
| C. | has an electric field directed along its length |
| D. | acts as a dipole |
| Answer» C. has an electric field directed along its length | |
| 717. |
At 0 K the forbidden energy gap in intrinsic semi conductor is about |
| A. | 10 eV |
| B. | 6 eV |
| C. | 1 eV |
| D. | 0.2 eV |
| Answer» D. 0.2 eV | |
| 718. |
In a bipolar transistor, the base collector junction has |
| A. | forward bias |
| B. | reverse bias |
| C. | zero bias |
| D. | zero or forward bias |
| Answer» C. zero bias | |
| 719. |
Determine the transistor capacitance of a diffused junction varicap diode of a reverse potential of 4.2 V if C(0) = 80 pf and VT = 0.7 V |
| A. | 42 pf |
| B. | 153.03 pf |
| C. | 13.33 pf |
| D. | Data inadequate |
| Answer» B. 153.03 pf | |
| 720. |
In p type semiconductors the conduction due to holes ( = σp ) is (where e = charge on hole, μp is hole mobility and ρ is hole concentration) |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 721. |
The Ebers-moll equation for IE in CB configuration is given by |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 722. |
The small signal input impedance of a transistor whose output is shorted for the measuring signal is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 723. |
To avoid thermal runaway in the design of an analog circuit, the operating point of the BJT should be such that it satisfies the condition. |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 724. |
Hall coefficient KH and charge density ρ are related as |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 725. |
An one sided abrupt junction has 10²¹/m³ of dopants on the lightly doped side, zero bias voltage and a built-in potential of 0.2 V. The depletion width of abrupt junction.(q = 1.6 x 10¯¹⁹ C, εr =16, ε₀ = 8.87 x 10¯¹² F/m) is |
| A. | 0.036 nm |
| B. | 0.6 μm |
| C. | 3 mm |
| D. | 1.5 mm |
| Answer» C. 3 mm | |
| 726. |
In common base configuration, the input characteristics of bipolar junction transistor are drawn between |
| A. | VEB and IE |
| B. | VCB and IC |
| C. | IC and VCE |
| D. | IE and VCE |
| Answer» B. VCB and IC | |
| 727. |
Assertion (A): In n-p-n transistor conduction is mainly due to electrons.Reason (R): In n type materials electrons are majority carriers. |
| 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 | |
| 728. |
In a semi-conductor diode, the barrier offers opposition to |
| A. | holes in P-region only |
| B. | free electrons in N-region only |
| C. | majority carriers in both regions |
| D. | majority as well as minority carriers in both regions |
| Answer» D. majority as well as minority carriers in both regions | |
| 729. |
Which of the following is used for generating time varying wave forms? |
| A. | MOSFET |
| B. | PIN diode |
| C. | Tunnel diode |
| D. | UJT |
| Answer» E. | |
| 730. |
Consider the following statements. 1. Etching2. Exposure to UV radiation3. Stripping4. Developing After a wafer has been coated with photo resist the correct sequence of these steps in photolithography is |
| A. | 2, 4, 3, 1 |
| B. | 2, 4, 1, 3 |
| C. | 4, 2, 1, 3 |
| D. | 3, 2, 3, 1 |
| Answer» D. 3, 2, 3, 1 | |
| 731. |
Assertion (A): The conductivity of p type semiconductor is higher than that of intrinsic semiconductor.Reason (R): The addition of donor impurity creates additional energy levels below conduction band. |
| 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» C. A is true but R is false | |
| 732. |
One electron volt is equivalent to |
| A. | 1.6 x 10¯¹ᴼ joule |
| B. | 1.6 x 10¯¹³ joule |
| C. | 1.6 x 10¯¹⁶ joule |
| D. | 1.6 x 10¯¹⁹ joule |
| Answer» E. | |
| 733. |
Hall effect can be used |
| A. | to find type of semiconductor (whether p or n) |
| B. | to find carrier concentration |
| C. | to measure conductivity |
| D. | all of the above |
| Answer» E. | |
| 734. |
Recombination produces new electron-hole pairs |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 735. |
The number of doped regions in PIN diode is |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 1 or 2 |
| Answer» C. 3 | |
| 736. |
Semiconductors have |
| A. | aero temperature coefficient of resistance |
| B. | positive temperature coefficient of resistance |
| C. | negative temperature coefficient of resistance |
| D. | none of the above |
| Answer» D. none of the above | |
| 737. |
At room temperature a semiconductor material is |
| A. | perfect insulator |
| B. | conductor |
| C. | slightly conducting |
| D. | any of the above |
| Answer» D. any of the above | |
| 738. |
A reverse voltage of 18 V is applied to a semiconductor diode. The voltage across the depletion layer is |
| A. | 0 V |
| B. | 0.7 V |
| C. | about 10 V |
| D. | 18 V |
| Answer» E. | |
| 739. |
An LED is |
| A. | an ohmic device |
| B. | a display device |
| C. | a voltage regulated device |
| D. | all of the above |
| Answer» C. a voltage regulated device | |
| 740. |
In CE configuration, the output characteristics of a bipolar junction transistor is drawn between |
| A. | IC and VCB |
| B. | IE and VCB |
| C. | IC and VCE |
| D. | IE and VCE |
| Answer» D. IE and VCE | |
| 741. |
The circuit shown in the figure is best described as a |
| A. | bridge rectifier |
| B. | ring modulator |
| C. | frequency discriminator |
| D. | voltage doubler |
| Answer» E. | |
| 742. |
Which is correct for a vacuum triode? |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 743. |
The current density J, free electron mobility μn, hole mobility μp , magnitude of free electron and hole concentration ni electric field E and charge on electron e, in intrinsic semiconductor are related as |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 744. |
In bipolar transistors dc current gain is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 745. |
The O/P char, of a FET is given in the figure. In which region is the device biased for small signal amplification? |
| A. | AB |
| B. | BC |
| C. | CD |
| D. | BD |
| Answer» C. CD | |
| 746. |
The current in a p-n junction diode with V volts applied in p region relative to n region (where I0 is reverse saturation current, m is ideality factor, k is Boltzmann's constant, T is absolute temp and q is charge on electron) is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 747. |
Which of these has semi-conductor metal junction? |
| A. | PIN diode |
| B. | Photo diode |
| C. | Tunnel diode |
| D. | Schottky diode |
| Answer» E. | |
| 748. |
Figure shows small signal common base transistor circuit.The current source I and resistor R on the output side are |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 749. |
The Ni-Zn ferrites are used for audio and TV transformers is that |
| A. | they have large saturation magnetisation |
| B. | they are easy to fabricate by rolling |
| C. | they are free from pores and voids |
| D. | they have high electro-resistivity |
| Answer» B. they are easy to fabricate by rolling | |
| 750. |
In a bipolar transistor, the emitter base junction has |
| A. | forward bias |
| B. | reverse bias |
| C. | zero bias |
| D. | zero or reverse bias |
| Answer» B. reverse bias | |