CareerRide--Electronics Devices & Circuits

Biasing of D-MOSFET in saturation or non-saturation region while using with depletion load device, specifically depends on ______ - Published on 24 Sep 15 a. VDD & Rs b. VDD & VDS c. VDD & ID d. ID & Rs

a

Fidelity is nothing but an ability of amplifier to reproduce ________ - Published on 23 Sep 15 a. Input signal without any distortion b. Output signal without any distortion c. Phase shift signal d. Amplitude shift signal

a

Multivibrators belong to the category of _____________ - Published on 23 Sep 15 a. Square wave oscillators b. Triangular wave oscillators c. Ramp wave oscillators d. Sinusoidal oscillators

a

The output signal generated corresponding to the magnified input signal by a linear amplifier is _________ A. Larger in size B. Smaller in size C. Similar in shape as that of input signal D. Different in shape as that of input signal - Published on 23 Sep 15 a. A & C b. B & D c. B & C d. A & D

a

The slope of AC load line is usually ____________ - Published on 23 Sep 15 a. Higher than slope of DC load line b. Smaller than slope of DC load line c. Similar as that of DC load line d. None of the above

a

The value of dBm in power measurement is estimated by assuming the reference ,which is equal to ________ - Published on 23 Sep 15 a. 1mW b. 10mW c. 1/10 mW d. 1/100 mW

a

The value of transconductance decreases in simplified low frequency equivalent circuit of n-channel MOSFET due to increase in the value of _______ - Published on 24 Sep 15 a. Source resistance b. Load resistance c. Both a and b d. None of the above

a

What should be the level of input resistance to allow the occurrence of source loading in common base amplifier configuration? - Published on 23 Sep 15 a. Low b. High c. Moderate d. Stable

a

Which among the below specified conditions is applicable to prevent the occurrence of thermal runaway in voltage divider bias circuit? - Published on 24 Sep 15 a. VCE < VCC / 2 b. VCE = VCC / 2 c. VCE > VCC / 2 d. None of the above

a

Which among the below specified parameters exhibit inverse relationship with an input conductance of hybrid π model? - Published on 23 Sep 15 a. Temperature at constant hfe b. Current at constant hfe c. Voltage at constant hre d. Resistivity at constant hre

a

Which among the below stated transistors operate in an active region for the purpose of amplification? - Published on 23 Sep 15 a. BJT b. E-MOSFET c. Both a and b d. None of the above

a

Which among the following oscillators are specifically preferred at high frequencies? - Published on 24 Sep 15 a. LC oscillators b. RC oscillator c. Both a and b d. None of the above

a

Which among the following parameters acts as an initiator for the operation of an oscillator in the absence of input signal? - Published on 23 Sep 15 a. Noise voltage b. Noise power c. Noise temperature d. Noise figure

a

Which among the following will possess a higher bandwidth, if two transistors are provided with unity gain frequency? - Published on 23 Sep 15 a. Transistor with lower hfe b. Transistor with higher hfe c. Transistor with lower hre d. Transistor with higher hre

a

Which capacitance/s in hybrid π model represent/s the storage of excess minority carriers at the base emitter junction? - Published on 23 Sep 15 a. Diffusion capacitance b. Transition capacitance c. Both a and b d. None of the above

a

Which condition is applicable for a body to be more positive than source in a small signal equivalent circuit of N-type MOSFET inclusive of body effect? - Published on 24 Sep 15 a. Vbs > 0 b. Vbs < 0 c. Vbs = 0 d. None of the above

a

Which is the necessary condition of gain while designing RC phase shift oscillator in order to ensure the sustained oscillations? - Published on 23 Sep 15 a. A ≥ 29 b. A ≤ 29 c. A ≠ 29 d. None of the above

a

Which is/are the major drawback/s of including an additional n__drift layer in a typical n-p-n bipolar power transistor? - Published on 23 Sep 15 a. Increase in on-state device resistance by increasing on-state power loss b. Increase in on-state device resistance by decreasing on-state power loss c. Increase in on-state device resistance by completely stabilizing the level of on-state power loss d. All of the above

a

Which process plays a crucial role in devising the independency of operating point over the variations in temperature or transistor parameters? - Published on 24 Sep 15 a. Bias stabilization b. Bias compensation c. Both a and b d. None of the above

a

Which resistance plays a significant role in stabilization of Q-point for self-biasing circuit of BJT? - Published on 24 Sep 15 a. Emitter resistance b. Collector resistance c. Source resistance d. Drain resistance

a

Which types of power transistors have the capability to withstand the higher junction temperatures? - Published on 24 Sep 15 a. Silicon power transistors b. Germanium power transistors c. Both a and b d. None of the above

a

Why do the internal capacitances of transistor at low frequencies treated as open circuits by completely neglecting their effects in analysis? - Published on 23 Sep 15 a. Due to high reactance b. Due to low reactance c. Due to moderate reactance d. None of the above

a

Why is the Darlington configuration not suitable for more than two transistors? - Published on 24 Sep 15 a. Because leakage current increases and voltage gain decreases with multiple number of transistors b. Because leakage current decreases and voltage gain increases with multiple number of transistors c. Because leakage current as well as voltage gain increases with multiple number of transistors d. Because leakage current as well as voltage gain decreases with multiple number of transistors

a

According to the property of tuned circuit used in LC oscillators, the decay rate is proportional to________ - Published on 24 Sep 15 a. Shape & size of current pulse b. Time constant c. Both a and b d. None of the above

b

Near-avalanche breakdown in MOSFET is an ultimate outcome of _________ - Published on 23 Sep 15 a. First order effects b. Second order effects c. Third order effects d. None of the above

b

On which factor does the current gain (β) of power transistor depend? - Published on 23 Sep 15 a. Thickness of emitter b. Thickness of base c. Thickness of collector d. All of the above

b

Subthreshold current is basically a drain current that flows only when __________ - Published on 23 Sep 15 a. VGS is slightly greater than VT b. VGS is slightly less than VT c. VGS is exactly equal to VT d. None of the above

b

The cut-off frequency (fβ) is basically the frequency at which the short circuit __________ - Published on 23 Sep 15 a. CB gain of transistor drops by 3 dB from its value at low frequency b. CE gain of transistor drops by 3 dB from its value at low frequency c. CC gain of transistor drops by 3 dB from its value at low frequency d. None of the above

b

The parameter 'h12' is basically a ratio of input voltage to the output voltage with the input current equal to _______ - Published on 23 Sep 15 a. Unity b. Zero c. Infinity d. None of the above

b

The rate of -20 dB/decade is almost equivalent to __________ - Published on 23 Sep 15 a. -4 dB/octave b. -6 dB/octave c. -8 dB/octave d. -10 dB/octave

b

What are the consequences over the non-linear distortion by the inception of negative feedback? - Published on 24 Sep 15 a. Level of non-linear distortion goes on increasing b. Level of non-linear distortion goes on decreasing c. Level of non-linear distortion undergoes stability d. None of the above

b

What is an angle of phase shift for each designed RC network in the Phase Shift Oscillator circuit? - Published on 23 Sep 15 a. 30° b. 60° c. 90° d. 180°

b

What should be the gain of an amplifier at 20 kHz if the half power frequencies are fL = 20 Hz and fH = 15 kHz along with mid band gain = 80? - Published on 23 Sep 15 a. 28.28 b. 48.07 c. 62.47 d. 78.77

b

What would happen if 180° phase shifted signal between input voltage (Vi) and drain-to-source voltage (VGS) will be passed through the output coupling capacitor during the operation of MOSFET as an amplifier? - Published on 23 Sep 15 a. DC value will be reduced to unity b. DC value will be reduced to zero c. DC value will be reduced to infinity d. None of the above

b

What would happen, if the signal Xd passes through the feedback network? - Published on 24 Sep 15 a. Xd will get multiplied by 'A' b. Xd will get multiplied by 'β' c. Xd will get multiplied by '1 - Aβ' d. Xd will get multiplied by '1 + Aβ'

b

Where should be the position of Q point on the load line, if the transistor is used for amplification purpose? - Published on 23 Sep 15 a. At the point of inception (initial point) b. At the center c. At the eventual point (final point) d. None of the above

b

Which among the below mentioned circuits resemble its behaviour similar to that of an amplifier in high frequency region, as the response decreases with an increase in frequency? - Published on 24 Sep 15 a. Simple high pass circuit b. Simple low pass circuit c. Simple band pass circuit d. Simple band stop circuit

b

Which among the below mentioned devices acts as a driver in CMOS Inverter Circuit? - Published on 24 Sep 15 a. PMOS b. NMOS c. Both a and b d. None of the above

b

Which among the below mentioned implementation strategies is/are precise to obtain an AC equivalent circuit of MOSFET? A. Replacement of all capacitors by open circuits B. Replacement of all capacitors by short circuits C. Setting of all DC voltages to zero D. Setting of all DC voltages to unity - Published on 23 Sep 15 a. A & C b. B & C c. B & D d. A & D

b

Which among the below specified conditions is responsible to drive a low resistance load by the current amplifier circuit? - Published on 23 Sep 15 a. Rs >> Ri b. R0 >> RL c. Rs << Ri d. R0 << RLv

b

Which among the following is an output provided by transresistance amplifier? - Published on 23 Sep 15 a. Output current proportional to signal voltage b. Output voltage proportional to signal current c. Output voltage proportional to input voltage d. Output current proportional to signal current

b

Which among the following plays a cardinal role in providing the transition capacitance in hybrid π model? - Published on 23 Sep 15 a. Forward biased base-emitter junction b. Reverse-biased collector base junction c. Forward biased collector base junction d. Reverse-biased base-emitter junction

b

Which capacitors assists in preventing the loss of gain due to negative feedback without affecting the DC stability of R-C Coupled amplifier? - Published on 24 Sep 15 a. Coupling capacitors (Cc) b. Bypass capacitors (CE) c. Both a and b d. None of the above

b

Which region/s in frequency response curve of an amplifier maintains the constant level of gain and output voltage? - Published on 23 Sep 15 a. Low Frequency Region b. Mid Frequency Region c. High Frequency Region d. All of the above

b

Which resistance in hybrid π model of transistor represents the bulk resistance present between the external base terminal and the virtual base? - Published on 23 Sep 15 a. Collector-to-emitter resistance (rce) b. Base spreading resistance (ŕbb) c. Virtual base to emitter resistance (ŕbe) d. None of the above

b

Which techniques is/are adopted for reducing the drift in the operating point especially when the loss of signal is intolerable? - Published on 24 Sep 15 a. Bias stabilization b. Bias compensation c. Both a and b d. None of the above

b

Which type of amplifiers exhibit the current gain approximately equal to unity without any current amplification? - Published on 23 Sep 15 a. CE b. CB c. CC d. None of the above

b

Which type of temperature dependent resistor exhibits a positive temperature coefficient of resistivity? - Published on 24 Sep 15 a. Thermistor b. Sensistor c. Both a and b d. None of the above

b

After passing through which circuit/network ,does the signal Xd (output signal obtained by taking the difference of two input signals) get multiplied by '-1'? - Published on 23 Sep 15 a. Amplifier circuit b. Feedback network c. Mixing network d. Sampling network

c

Generally, the resistance of thermistor decreases _______ - Published on 23 Sep 15 a. Linearly with an increase in temperature b. Linearly with the decrease in temperature c. Exponentially with an increase in temperature d. Exponentially with the decrease in temperature

c

Miller's theorem is applicable in a single stage CE hybrid π model in order to deal with ________ - Published on 24 Sep 15 a. Series combination of CC and r'bc b. Series combination of Ce and r'be c. Parallel combination of CC and r'bc d. Parallel combination of Ce and r'be

c

Stability of a transfer gain is generally defined as the reciprocal of _______ - Published on 24 Sep 15 a. Resistivity b. Conductivity c. Sensitivity d. Desensitivity

c

The breakdown voltage VCEV or VCEX in power transistor is the maximum voltage between collector and emitter with _________ - Published on 23 Sep 15 a. Open circuited collector b. Open circuited base c. Base to emitter voltage that is adjusted to a specific negative value d. Base to emitter voltage that is adjusted to a specific positive value

c

The n_region in a vertical cross-section of a typical n-p-n bipolar power transistor is also known as _________ - Published on 23 Sep 15 a. Emitter drift region b. Base drift region c. Collector drift region d. None of the above

c

What are the consequences of diode compensation for the change in base-to-emitter voltage (VBE) due to temperature? - Published on 23 Sep 15 a. Temperature compensation takes place by variation in forward voltage (VF) b. Collector current become insensitive to the change in base-to-emitter voltage (VBE) c. Both a and b d. None of the above

c

What is /are the purpose/s of adopting stabilization and compensation techniques? - Published on 23 Sep 15 a. To provide maximum bias b. To provide thermal stabilization c. Both a and b d. None of the above

c

What is the effect of MOSFET biasing in the saturation region especially while representing the internal resistances and capacitances in n-channel E-MOSFET configuration? - Published on 24 Sep 15 a. Channel gets pinched off at the drain by increasing the value of Cgd b. Channel gets pinched off at the source by increasing the value of Cgd c. Channel gets pinched off at the drain by decreasing the value of Cgd upto zero d. Channel gets pinched off at the source by decreasing the value of Cgd

c

What is the phase-shift between input and output voltages of CE amplifier? - Published on 23 Sep 15 a. 90° b. 120° c. 180° d. 270°

c

What is the significance of adopting an interdigitated structure of power transistors? - Published on 24 Sep 15 a. Prevention of current crowding b. Maintenance of reasonable current densities c. Both a and b d. None of the above

c

What should be the value of input resistance for an ideal voltage amplifier circuit? - Published on 23 Sep 15 a. Zero b. Unity c. Infinity d. Unpredictable

c

What should be the value of transconductance, if N-channel E-MOSFET is biased in saturation region with the conduction parameter (k) = 0.836 mA/ V2 and drain current (ID) = 1.5 mA? - Published on 23 Sep 15 a. 1 mA/V b. 1.5 mA/V c. 2.23 mA/V d. 4.23 mA/V

c

What should be the value of unity gain frequency for a short circuit CE transistor with gain of 30 at 4MHz and cut-off frequency of about 100 kHz? - Published on 24 Sep 15 a. 40 MHz b. 80 MHz c. 120 MHz d. 150 MHz

c

What would be the computational value of feedback voltage in a negative feedback amplifier with A = 100, β = 0.03 and input signal voltage = 30 mV? - Published on 23 Sep 15 a. 0.03 V b. 0.06 V c. 0.09 V d. 0.15 V

c

Which among the below mentioned oscillators does not adopt any kind of feedback mechanism? - Published on 23 Sep 15 a. Phase-shift oscillator b. Wein bridge oscillator c. UJT relaxation oscillator d. All of the above

c

Which among the below stated notations of h-parameters is used to represent the short-circuit forward current transfer ratio? - Published on 24 Sep 15 a. h11 b. h12 c. h21 d. h22

c

Which among the following components is /are not involved in the feedback network configuration of LC oscillators? - Published on 23 Sep 15 a. Inductor b. Capacitor c. Resistor d. All of the above

c

Which among the following is not an advantage of RC coupled amplifiers? - Published on 24 Sep 15 a. High fidelity b. No core distortion c. No impedance matching d. Wide frequency response

c

Which among the following represents the frequency at which short circuit CE current gain acquires unit magnitude? - Published on 23 Sep 15 a. fα b. fβ c. fT d. None of the above

c

Which capacitor is used to block DC portion by allowing to pass only AC portion of the amplified signal to load? - Published on 23 Sep 15 a. Input Coupling Capacitor b. Bypass Capacitor c. Output Coupling Capacitor d. All of the above

c

Which type of breakdown effect gets enhanced due to parasitic BJT action along with increase in drain current solely by the reduction in size of MOSFET? - Published on 23 Sep 15 a. Near-avalanche breakdown b. Snapback breakdown c. Both a and b d. None of the above

c

Why is the practical value of | Aβ | considered or adjusted to be slightly greater than '1'? - Published on 23 Sep 15 a. To compensate for noise voltage b. To compensate for phase shifting of two relevant signals upto 180° c. To compensate for non-linearities existing in the circuit d. To compensate for the change in feedback voltage

c

Consider the assertions given below. A. Replacement of each coupling and bypass capacitors by a short circuit B. Replacement of transistor by its hybrid equivalent model for further analysis C. Replacement of DC voltage sources by a short circuit Which is the correct sequential order of steps to be carried out for analysis of a transistor amplifier circuit? - Published on 24 Sep 15 a. A, B, C b. B, A, C c. A, C, B d. C, A, B

d

On which factor/s do/does the value of thermal resistance depend? - Published on 24 Sep 15 a. Size of transistor b. Type of cooling system c. Type of heat transfer mechanism d. All of the above

d

Under which category/region of the below specified regions does EMOSFET operate for switching-based applications? - Published on 23 Sep 15 a. Saturation & Cut-off b. Active & Ohmic c. Only Saturation d. Ohmic & Cut-off

d

What is/ are the necessity /ies of using a vertical structure in Power BJTs? - Published on 23 Sep 15 a. Increase in cross-sectional area to allow the flow of device current b. Reduction in on-state power dissipation of transistor c. Reduction in thermal resistance to keep the problem of power dissipation under control d. All of the above

d

What should be the value of stability factor in voltage divider circuit, if the ratio RB / RE tends to infinity? - Published on 23 Sep 15 a. Unity b. Zero c. 1 - βdc d. 1 + βdc

d

Which among the below assertions is not a salient feature/ property of CE amplifier? - Published on 23 Sep 15 a. High voltage gain b. High current gain c. High input resistance d. High output resistance

d

Which among the below mentioned assertions is not a considerable factor to design a biasing circuit? - Published on 23 Sep 15 a. Position of Q point b. Value of collector current at Q point c. Maximum output swing without generating any distortion d. Transistor biasing in the circular portion of its transfer characteristics

d

Which among the below mentioned parameters of transistors is/are likely to get affected or exhibit/s variations due to increase in temperature? - Published on 23 Sep 15 a. Base-to-Emitter voltage (VBE) b. Reverse Saturation Current ( ICBO) c. Current Gain (βdc) d. All of the above

d

Which among the below mentioned reasons is/are responsible for the occurrence of second breakdown phenomenon in power BJT? - Published on 24 Sep 15 a. Large current b. Distribution of current in a non-uniform manner c. Excessive power dissipation d. All of the above

d

Which among the below stated consequences occur in the negative half-cycle during the operation of MOSFET as an amplifier? - Published on 23 Sep 15 a. Variation in VGS sinusoidally below VGSQ b. Variation in ID sinusoidally below IDQ c. Variation in voltage drop IDRD below its Q-point value d. All of the above

d

Which among the below stated parameters gets affected due to drift region in the power transistor? - Published on 24 Sep 15 a. Breakdown voltage b. On-state losses c. Switching time d. All of the above

d

Which among the following are specifically the advantages of bipolar design technology? A. High input resistance at low frequencies B. Zero input bias current C. High voltage gain D. High value of transconductance - Published on 24 Sep 15 a. A & B b. A & C c. B & D d. C & D

d

Which among the following does not belong to the category of LC oscillators? - Published on 23 Sep 15 a. Hartley oscillator b. Colpitt's oscillator c. Clapp oscillator d. Wein bridge oscillator

d

Which among the following measures is/are adopted/used for improving the frequency stability in Colpitt's oscillator? - Published on 24 Sep 15 a. Clapp oscillator b. Temperature stabilized chamber c. Voltage regulators d. All of the above

d

Which among the following parameter/s increase/s due to positive feedback? A. Input voltage B. Output Voltage C. Noise D. Voltage Gain - Published on 23 Sep 15 a. A & B b. Only C c. B & D d. A, B, C & D

d

Which type of breakdown can be prevented by adopting a reverse-biased gate protecting diode on input side of MOSFET? - Published on 23 Sep 15 a. Avalanche breakdown b. Punch through breakdown c. Snapback breakdown d. Static Charge Breakdown

d