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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.
| 751. |
In a junction transistor, the collector cut-off current 'ICB0' reduces considerably by doping the |
| A. | emitter with high level of impurity |
| B. | emitter with low level of impurity |
| C. | collector with high level of impurity |
| D. | collector with low level of impurity |
| Answer» B. emitter with low level of impurity | |
| 752. |
The O/P Power of a power amplifier is several times its input power. It is possible because |
| A. | power amplifier introduces a -ve resistance |
| B. | there is +ve feed back in the circuit |
| C. | step up transformer is use in the circuit |
| D. | power amplifier converts a part of I/Pc. power into a.c. power |
| Answer» E. | |
| 753. |
Light dependent resistors are |
| A. | highly doped semiconductor |
| B. | intrinsic semiconductor |
| C. | lightly doped semiconductor |
| D. | either (a) or (c) |
| Answer» D. either (a) or (c) | |
| 754. |
The current gain of a transistor is the ratio of |
| A. | emitter current to base current |
| B. | emitter current to collector current |
| C. | collector current to base current |
| D. | collector current to emitter current |
| Answer» D. collector current to emitter current | |
| 755. |
For an n-channel enhancement type MOSFET, if the source is connected at a higher potential than that of the bulk (VSB > 0), the threshold voltage VT of the MOSFET will |
| A. | remain unchanged |
| B. | decrease |
| C. | change Polarity |
| D. | increase |
| Answer» B. decrease | |
| 756. |
Assertion (A): Silicon is preferred over germanium in manufacture of semiconductor devices.Reason (R): Forbidden gap in silicon is more than that in germanium. |
| 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 | |
| 757. |
Consider the following circuit configuration 1. common Emitter2. common Base3. emitter follower4. emitter follower using Darlington pair. The correct sequence in increasing order of I/P impedance of these configuration: |
| A. | 2, 1, 4, 3 |
| B. | 1, 2, 4, 3 |
| C. | 2, 1, 3, 4 |
| D. | 1, 2, 3, 4 |
| Answer» C. 2, 1, 3, 4 | |
| 758. |
Ferrite have |
| A. | low copper loss |
| B. | low eddy current loss |
| C. | low resistivity |
| D. | higher specific gravity compared to iron |
| Answer» D. higher specific gravity compared to iron | |
| 759. |
In which n type device does p substrate extend upto silicon dioxide layer? |
| A. | JFET |
| B. | Depletion type MOSFET |
| C. | Enhancement type MOSFET |
| D. | Both (b) and (c) |
| Answer» D. Both (b) and (c) | |
| 760. |
For a photoconductor with equal electron and hole mobilities and perfect ohmic contacts at the ends, an increase in illumination results in |
| A. | a change in O.C. voltage |
| B. | a change in S.C. current |
| C. | a decrease in resistance |
| D. | an increase in resistance |
| Answer» D. an increase in resistance | |
| 761. |
As compared to an ordinary semiconductor diode, a Schottky diode |
| A. | has higher reverse saturation current |
| B. | has higher reverse saturation current and higher cut in voltage |
| C. | has higher reverse saturation current and lower cut in voltage |
| D. | has lower reverse saturation current and lower cut in voltage |
| Answer» D. has lower reverse saturation current and lower cut in voltage | |
| 762. |
The electric breakdown strength is affected by |
| A. | shape of the waveform of applied voltage |
| B. | steepness of the wavefront of the applied voltage |
| C. | composition of the material |
| D. | all of the above |
| Answer» E. | |
| 763. |
In standard TTL, the 'totem pole' stage refers to |
| A. | the multi-emitter I/P stage |
| B. | phase splitter |
| C. | the O/P buffer |
| D. | open collector O/P stage |
| Answer» D. open collector O/P stage | |
| 764. |
In n channel JFET |
| A. | ID and VDS are positive but VGS is negative |
| B. | ID and VGS are positive but VDS is negative |
| C. | VDS and VGS are positive but ID is negative |
| D. | ID, VDS and VGS are all positive |
| Answer» B. ID and VGS are positive but VDS is negative | |
| 765. |
Which variety of copper has the best conductivity? |
| A. | Pure annealed copper |
| B. | Hard drawn copper |
| C. | Induction hardened copper |
| D. | Copper containing traces of silicon |
| Answer» B. Hard drawn copper | |
| 766. |
In photo electric emission, the threshold frequency f0, work function Uw, and Planck's constant h are related as |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 767. |
The fT of a BJT is related to its gm, Cπ and Cμ as follows. |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 768. |
Ripple factor is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 769. |
The kinetic energy of free electrons in a metal is (where k is de-Broglie wave number of the electrons) |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 770. |
For a UJT ifR1 = Resistor from emitter to the base 1R2 = Resistor from emitter to the base 2 and RBB = R1 + R2, then the intrinsic stand off ratio (η) is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 771. |
R.M.S. value of the waveform shown will be |
| A. | 3.53 V |
| B. | 1 V |
| C. | 7.07 V |
| D. | 8.56 V |
| Answer» D. 8.56 V | |
| 772. |
In the figure shows the circuits symbol of |
| A. | FET |
| B. | PMOSFET |
| C. | CMOSFET |
| D. | NMOSFET |
| Answer» E. | |
| 773. |
Figure shows characteristics curves for bipolar transistor. These curves are |
| A. | output characteristics of n-p-n transistor (common base) |
| B. | output characteristics of p-n-p transistor (common base) |
| C. | output characteristics of n-p-n transistor (common emitter) |
| D. | output characteristics of p-n-p transistor (common emitter) |
| Answer» C. output characteristics of n-p-n transistor (common emitter) | |
| 774. |
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 the voltage across it does not fall below 6 V is |
| A. | 1.2 kΩ |
| B. | 80 Ω |
| C. | 50 W |
| D. | 0 |
| Answer» C. 50 W | |
| 775. |
For bipolar transistor |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 776. |
Discrete transistors T1 and T2 having maximum collector current rating of 0.75 amp are connected in parallel as shown in the figure, this combination is treated as a single transistor to carry a total current of 1 ampere, when biased with self bias circuit. When the circuit is switched on, T1 draws 0.55 amps and T2 draws 0.45 amps. If the supply is kept on continuously, ultimately it is very likely that |
| A. | Both T1, and T2 get damaged |
| B. | Both T1, and T2 will be safe |
| C. | T1 Will get damaged and T2 will be safe |
| D. | T2 will get damaged and T1, will be safe |
| Answer» D. T2 will get damaged and T1, will be safe | |
| 777. |
In given figure a silicon diode is carrying a constant current of 1 mA. When the temperature of the diode is 20°C, VD is found to be 700 mV. If the temperature rises to 40°C, VD becomes approximately equal to |
| A. | 747 mV |
| B. | 660 mV |
| C. | 680 mV |
| D. | 700 mV |
| Answer» B. 660 mV | |
| 778. |
The current through a PN Junction diode with v volts applied to the P region to the N region, where (I₀ is the reverse saturation current to the diode, m the ideality factor, k the Boltzmann constant, T the absolute temperature and q the magnitude of charge on an electron) is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 779. |
Typical values of h parameters at about 1 mA collector current for small signal audio amplifier in CE configuration are : |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 780. |
In a P-type semiconductor, the conductivity due to holes (= σP) is equal to e = charge of hole, μP = hole mobility, P = hole concentration, |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 781. |
CE saturation resistance of n-p-n transistor is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 782. |
The network shown in the figure represents a |
| A. | band pass filter |
| B. | low pass filter |
| C. | high pass filter |
| D. | band stop filter |
| Answer» B. low pass filter | |
| 783. |
In a junction transistor biased for operation at emitter current 'IE' and collector current 'IC' the transconductance 'gm' is. |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 784. |
Figure shows the terminals of a transistor in plastic package TO 18. Then |
| A. | terminals 1, 2, 3 are emitter, collector, base respectively |
| B. | terminals 1, 2, 3 are emitter, base, collector respectively |
| C. | terminals 1, 2, 3 are base, emitter collector, respectively |
| D. | terminals 1, 2, 3 are collector, emitter, base respectively |
| Answer» C. terminals 1, 2, 3 are base, emitter collector, respectively | |
| 785. |
GaAs has an energy gap 1.43 eV the optical cut off wavelength of GaAs would lie in the |
| A. | visible region of the spectrum |
| B. | infrared region of the spectrum |
| C. | ultraviolet region of the spectrum |
| D. | for ultraviolet region of the spectrum |
| Answer» C. ultraviolet region of the spectrum | |
| 786. |
In a zener diode |
| A. | forward voltage rating is high |
| B. | negative resistance characteristics exists |
| C. | sharp breakdown occurs at low reverse voltage |
| D. | none of the above |
| Answer» D. none of the above | |
| 787. |
When P-N junction is in forward bias, by increasing the battery voltage |
| A. | current through P-N junction reduces |
| B. | current through P-N junction increases |
| C. | circuit resistance increases |
| D. | none of the above |
| Answer» C. circuit resistance increases | |
| 788. |
Assertion (A): Oxide coated cathodes are very commonly used.Reason (R): Work function of oxide coated cathode is 1 eV whereas it is 4.5 eV for pure tungsten. |
| 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 | |
| 789. |
In the BJT amplifier shown in the figure is the transistor is biased in the forward active region. Putting a capacitor across RE will |
| A. | decrease the voltage gain and decrease the I/P impedance |
| B. | increase the voltage gain and decrease the I/P Impedance |
| C. | decrease the voltage gain and Increase the I/P impedance |
| D. | none of the above |
| Answer» C. decrease the voltage gain and Increase the I/P impedance | |
| 790. |
Assertion (A): A p-n junction is used as rectifier.Reason (R): A p-n junction has low resistance in forward direction and high resistance in reverse direction. |
| 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 | |
| 791. |
The mean life time of carrier may range from 10¯⁹ seconds to hundreds of μ-seconds. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 792. |
The v-i characteristic of an element is shown in below figure the element is |
| A. | non-linear, active, non-bilateral |
| B. | linear, active, non-bilateral |
| C. | non-linear, passive, non-bilateral |
| D. | non-linear, active, bilateral |
| Answer» E. | |
| 793. |
The maximum rectification efficiency in case of full wave rectifier is |
| A. | 100% |
| B. | 81.2% |
| C. | 66.6% |
| D. | 40.6% |
| Answer» C. 66.6% | |
| 794. |
Which statement is false as regards holes |
| A. | Holes exist in conductors as well as semiconductors |
| B. | Holes constitute positive charges |
| C. | Holes exist only in semiconductors |
| D. | Holes and electrons recombine |
| Answer» B. Holes constitute positive charges | |
| 795. |
In a bipolar junction transistor the base region is made very thin so that |
| A. | recombination in base region is minimum |
| B. | electric field gradient in base is high |
| C. | base can be easily fabricated |
| D. | base can be easily biased |
| Answer» B. electric field gradient in base is high | |
| 796. |
The band gap of silicon at 300K is |
| A. | 1.36 eV |
| B. | 1.10 eV |
| C. | 0.80 eV |
| D. | 0.67 eV |
| Answer» C. 0.80 eV | |
| 797. |
An electron rises through a voltage of 100 V. The energy acquired by it will be |
| A. | 100 eV |
| B. | 100 joules |
| C. | (100)^1.2 eV |
| D. | (100)^1.2 joules |
| Answer» B. 100 joules | |
| 798. |
A thermistor is a |
| A. | thermocouple |
| B. | thermometer |
| C. | miniature resistance |
| D. | heat sensitive explosive |
| Answer» D. heat sensitive explosive | |
| 799. |
When diodes are connected in series to increase voltage rating the peak inverse voltage per junction |
| A. | should not exceed half the breakdown voltage |
| B. | should not exceed the breakdown voltage |
| C. | should not exceed one third the breakdown voltage |
| D. | may be equal to or less than breakdown voltage |
| Answer» D. may be equal to or less than breakdown voltage | |
| 800. |
When the light falling on a photodiode increases, the reverse minority current |
| A. | increases |
| B. | increases or decreases |
| C. | decreases |
| D. | remains the same |
| Answer» B. increases or decreases | |