Basic Electronics Engineering Test Questions Set 9

1)   What are the possible phases for linearizing the circuits at the input signal conditioning stage of data logger?

a. At the analog phase before conversion
b. At the conversion phase
c. After the digital phase after the conversion
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
No explanation is available for this question!


2)   Which device/s is/are utilized for the printing purpose of the output generated by the data loggers?

a. Typewriter
b. Strip Printer
c. Magnetic Tape
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
No explanation is available for this question!


3)   What does the sequential operation of setting the linearization factor at the programming level of data loggers convey?

a. Adjusted Output from signal amplifier is directly proportional to the measured quantity
b. Adjusted Output from signal amplifier is inversely proportional to the measured quantity

c. Adjusted Input from signal amplifier is directly proportional to the measured quantity
d. Adjusted Input from signal amplifier is inversely proportional to the measured quantity
Answer  Explanation  Related Ques

ANSWER: Adjusted Output from signal amplifier is directly proportional to the measured quantity

Explanation:
No explanation is available for this question!


4)   Which module of PC based alarm annunciator system generates the log file so as to maintain the status of text-based information in accordance to the written records of master database?

a. Input Module
b. Output Module
c. Control Module
d. Server Module
Answer  Explanation  Related Ques

ANSWER: Output Module

Explanation:
No explanation is available for this question!


5)   Which library call status support the implementation of control module especially for controlling all other associated modules in time-slice fashion?

a. Dynamic Linkage Library (DLL) Call
b. Timer Call of MFC Library
c. Modulo Call of MFC Library
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Timer Call of MFC Library

Explanation:
No explanation is available for this question!


6)   Which circuit configuration basically reduces the probability of interference in an overall PC based alarm annunciator system?

a. Interfacing Circuit
b. Firewall Circuit
c. Router-oriented Circuit
d. Panel-based Circuit
Answer  Explanation  Related Ques

ANSWER: Interfacing Circuit

Explanation:
No explanation is available for this question!


7)   Which unit of PIC undergo the process of converting mains ac voltage to low dc voltage required for the circuits and the input-output interfacing modules?

a. Memory Unit
b. Processing Unit
c. Input/Output Unit
d. Power Supply Unit
Answer  Explanation  Related Ques

ANSWER: Power Supply Unit

Explanation:
No explanation is available for this question!


8)   Which bus forms an intermediate communication path between input/output ports and input/output units?

a. Control Bus
b. Data Bus
c. Address Bus
d. System Bus
Answer  Explanation  Related Ques

ANSWER: System Bus

Explanation:
No explanation is available for this question!


9)   Which kind of switches examine or detect the presence of an item or object without making contact with them?

a. Proximity Switches
b. Reed Switches
c. Photo-electric Switches
d. Mechanical Switches
Answer  Explanation  Related Ques

ANSWER: Proximity Switches

Explanation:
No explanation is available for this question!


10)   Which machine tools are basically handled and controlled by Computer Numerical Control (CNC) machine especially at the manufacturing sector?

a. Lathes
b. Routers
c. Mills & Grinders
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
No explanation is available for this question!


11)   Why is it mandatory to use or connect a level translator circuit after the intermediate stage in a typical operational amplifier?

a. For Phase level shifting
b. For DC level shifting
c. For AC level shifting
d. Both AC & DC Level shifting
Answer  Explanation  Related Ques

ANSWER: For DC level shifting

Explanation:
Level shifter or translator is usually connected in a typical Op-Amp so as to shift the DC Level at the output of intermediate stage which is grounded onward to zero. Intermediate stage is basically a differential amplifier which is driven by the previous state output. The DC Level at the output of intermediate stage is good above ground potential in case of direct coupling. Hence, it is obligatory to use the level shifter in OP-Amps.


12)   Which among the following is an incorrect characteristic of an ideal Op-Amp?

a. Infinite CMRR & Slew Rate
b. Infinite Voltage gain
c. Infinite Bandwidth
d. Infinite output offset voltage when input voltage is zero
Answer  Explanation  Related Ques

ANSWER: Infinite output offset voltage when input voltage is zero

Explanation:
An ideal Op-Amp has an infinite CMRR, Slew Rate & Bandwidth. But, the output voltage is absolutely zero when the input voltage is zero. All the mentioned parameters tend to infinity except output voltage & resistance so that it becomes feasible for an output to drive infinite number of other devices.


13)   Which of the below stated condition/s is applicable for Non-inverting amplifier?

a. Output Voltage is greater than input voltage
b. Output voltage is lesser than input voltage
c. Output voltage is in phase with an input signal
d. Output voltage is out of phase w.r.t. input by 180°


a. A & D
b. A & C
c. B & D
d. B & C
Answer  Explanation  Related Ques

ANSWER: A & C

Explanation:
Non-inverting amplifier has greater output voltage than that of its input voltage & is in phase with it. On the contrary, the output voltage of inverting Op-amp goes out of phase in correspondence to input signal by an angle of 180° or in terms of opposite polarity. In case of non-inverting amplifier, the input is applied to non-inverting input terminal & inverting terminal is set to be grounded while in case of inverting amplifier, the input is applied to inverting terminal & non-inverting terminal is at ground level. Therefore, due to the configurational assortments in inverting & non-inverting amplifier, the output voltage & phase level (in or out) also exhibit variations.


14)   The amplification difference level of a differential amplifier specifically & configurationally resemble to ______.

a. Wein Bridge
b. Kelvin Bridge
c. Wheatstone Bridge
d. Maxwell Bridge
Answer  Explanation  Related Ques

ANSWER: Wheatstone Bridge

Explanation:
Structural Configuration of a differential amplifier is semantic to wheatstone bridge since the amplification is done between two input signals in exactly similar way just like the outputs of Wheatstone bridge network. The cardinality of differential amplifier can be most probably seen in industrial & instrumentation aspects due to superior ability of rejecting common mode noise voltages.


15)   Why are the Op-amps with open loop configuration not used in linear applications?

a. High risk of distortion
b. High risk of clipping of output signal
c. Both a & b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Both a & b

Explanation:
Open loop configuration of Op-amp may increase the threat of distortion as well as clipping of output signal. Due to this reason, the output gets switched between the positive and negative saturation levels. Hence, this is the major drawback because of which it is highly impossible to use Op-amps with open loop configurations in linear circuit applications.


16)   Variation in the thermal drift can be observed whenever there is a change in ______.

a. Temperature
b. Supply Voltages
c. Time
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
The thermal drift phenomenon of voltage & current are taken into consideration in accordance to the values of input offset voltage, input bias current & input offset current. However, variations in these parameters ultimately changes the level of thermal drift (Drift voltage & Drift current).


17)   The quantity of output offset voltage due to input bias current can be crucially decreased by

a. Offset minimizing resistors
b. Offset minimizing voltage controller
c. Offset minimizing capacitors
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Offset minimizing resistors

Explanation:
Offset minimizing resistors are the only means of reducing the amount of output offset voltage. Voltage Controllers & capacitors are not meant for controlling the amount of offset output voltage in Op-amps.


18)   Which amplifier has an ability to amplify each input voltage & deliberately can be represented by the different factors at the output under the category of inverting amplifiers?

a. Summing Amplifier
b. Scaling Amplifier
c. Averaging amplifier
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Scaling Amplifier

Explanation:
Inverting amplifiers are generally categorized in the form of summing amplifier, Scaling amplifier and averaging amplifier. Basically, each input voltage gets amplified by a different factor & then weighted differently at the output level. Hence, this scaling amplifier is also referred as 'Weighted Amplifier'. This can only be possible when all input resistances belong to the different values. On the controversial aspect, summing amplifier generates the output voltage which is equal to negative summation of all inputs times the circuit gain. Apart from this, average circuit produces the output voltage by considering the average of all input voltages. Only the scaling or (weighted amplifiers) possesses this characteristic of operation that exhibits different weightages at the output.


19)   The major role of an instrumentation amplifier contributes to the amplification of ______.

a. Low-level Output Signal
b. High Level Output Signal
c. Both a & b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Low-level Output Signal

Explanation:
The leading role of an instrumentation amplifier signifies is the amplification & magnification of low level signals in order to drive the display or an indicator. High level signal does not need to get amplify & therefore, instrumentation amplifiers are targeted to amplify low level signals semantically where there is necessity of low noise, low thermal & time drifts, high input resistance & precise closed-loop gain. Besides these, instrumentation amplifiers like μ A725, ICL 7605 & LH0036 find their wide range of applications due to dexterity in precision & stability at the most confined level.


20)   Sensitivity of strain gauge implies _____.

a. Unit change in R per unit change in 'l'
b. Unit change in L per unit change in 'l'
c. Unit change in C per unit change in 'l'
d. Unit change in Y per unit change in 'l'
Answer  Explanation  Related Ques

ANSWER: Unit change in R per unit change in 'l'

Explanation:
Sensitivity is basically a dimensionless quantity & implies the change in resistance due to change in length of wire at a unity level. Generally, there are mainly two types of strain gauges like wired strain gauge & semiconductor strain gauge. Semiconductor strain gauges are sensitive to maximum extent as compared to that of wire type & hence they yield more accuracy and resolution. Intuitively, sensitivity measures the degree of accuracy & resolution. More the level of sensitivity, high will be the rate of accuracy & resolution.


21)   What kind of configuration will be formed/set up by replacing a meter with relay along with the usage of a thermistor in the transducer bridge circuit of a differential instrumentation amplifier?

a. Temperature Indicator
b. Temperature Controller
c. Light-intensity meter
d. Thermal Conductivity meter
Answer  Explanation  Related Ques

ANSWER: Temperature Controller

Explanation:
Temperature control circuit can be built up by using a thermistor in bridge circuit along with the replacement of a meter by a relay in the structural configuration of differential instrumentation amplifier. It is possible to control the current in the heat-generating circuit with an assistance of relay driven by the temperature controller itself. Temperature indicator is also constructed using thermistor as a transducer with the only difference that output meter is calibrated in degree Celsius or Fahrenheit. Despite bridge circuits, light-intensity meter can be built-up by using a photocell as a transducer while two thermistors are adjacently connected in thermal conductivity meter circuits.


22)   In darkness, the typical value of the resistance of photo-conductive cell lies in the order of _____.

a. 10 ohm
b. 100 ohm
c. 1000 ohm
d. 10000 ohm
Answer  Explanation  Related Ques

ANSWER: 100 ohm

Explanation:
Photo-conductive cells can be categorized under the family of photo-detectors which shows variation in the resistance due to incidence of light or any other form of radiant energy. The resistance value decreases with an increase in the intensity of incident light & hence the typical value of resistance of photo-conductive cells is absolutely 100 ohm. Materials like cadmium sulphide and silicon are used for photo conductive cells to greater extent since their conductivity is a function of incident radiant energy. Resistances of photo-conductive cell are noted along with the corresponding light intensities & then the resistances are expressed in terms of ohm while the light intensities are expressed in terms of meter candles (lux).


23)   Which among the following condition is applicable for the output voltage in an integrator?

a. Output voltage is directly proportional to negative integral of input voltage
b. Output voltage is directly proportional to positive integral of input voltage
c. Output voltage is inversely proportional to time constant RC
d. Output voltage is inversely proportional to phase constant


a. A & D
b. B & D
c. A & C
d. B & C
Answer  Explanation  Related Ques

ANSWER: A & C

Explanation:
Integrator is basically a circuit where the output voltage forms an integral part of input voltage. If the feedback resistor gets replaced by a capacitor in a basic inverting amplifier, then the integrator circuit can be produced. If an input is in the form of a sinusoidal waveform then the output will generate a cosine waveform due to direct relationship of output voltage and negative negative integral of input voltage. Even, phase constant is not involved in case of differentiator & integrator. However, only the case of A & C is application from the integrator point of view.


24)   The process of converting an original cut-off frequency to new cut-off frequency is known as

a. Frequency Deviation
b. Frequency Translation
c. Frequency Division
d. Frequency Scaling
Answer  Explanation  Related Ques

ANSWER: Frequency Scaling

Explanation:
Frequency Scaling is a process of conversion of original cut-off frequency to a new cut-off frequency. Here, the frequency gets converted & not deviated or translated or divided before the conversion process. Frequency Scaling is most oftenly performed whenever there is a necessity to change the cut-off frequencies in filter designing process. Multiplication of either 'R' or 'C' by the ratio of original cut-off frequency to the new cut-off frequency gives a notion for changing the high cut-off frequency.


25)   What will be the figure of merit or quality factor (Q) for a band-pass filter to be wide?

a. Greater than 10
b. Less than 10
c. Equal to 10
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Less than 10

Explanation:
Narrow & Wide band-pass filters can be distinguished only on the basis of quality factor. This figure of merit conveys that if 'Q' > 10, the filter is considered to be a narrow band-pass filter whereas if 'Q' < 10, then the filter is considered as a narrow band-pass filter. Therefore, quality factor is a measure of selectivity which infers that the selectivity of the filter depends on the value of 'Q'. Higher the value of quality factor, more is the selectivity of the filter.


26)   Notch-filter is the renowned name of _____.

a. Band-elimination Filter
b. Band pass Filter
c. Wide-band reject filter
d. Narrow band reject filter
Answer  Explanation  Related Ques

ANSWER: Narrow band reject filter

Explanation:
Band-reject filters are those which shows the frequency attenuation in the stop-band while they get passed outside this band. Similar to band-pass filters, band-reject filters also gets classified into wide & narrow band-reject filters. Narrow band-reject filter is commonly known as notch filter since it has high quality factor (Q>10) & bandwidth is very much smaller as compared to that of wide band-reject filters.
These narrow band-reject filters are widely used for single frequency rejection like 60 Hz power line frequency hum. For an instance, twin-T network. Notch filter finds its applications in the aspects of communication & biomedical instruments so as to remove the unwanted frequencies.


27)   Which among the following are also known as “Delay Equalizers”?

a. Band Elimination Filter
b. Band-pass Filter
c. All-pass Filter
d. High pass filter
Answer  Explanation  Related Ques

ANSWER: All-pass Filter

Explanation:
All-pass filters allows to pass all the frequency components of input signal without any attenuation by anticipating phase shifts for different frequencies. When signals undergo transmission by telephone wires, there is a definite change in phase. Thus, all pass filters are the means for compensating these phase changes, because of which they are generally termed as “Phase-Correctors” or “Delay Equalizers”. Output of Delay Equalizers can be generated by using Super-position theorem.


28)   Match the following : Types Waveform Generation Type

a. RC Oscillator ---------------------------------- 1. Saw-tooth wave
b. LC Oscillator ----------------------------------- 2. Sinusoidal wave
c. Crystal Oscillator ----------------------------- 3. Square wave


a. A3, B2, C1
b. A2, B3, C1
c. A1, B2, C3
d. A1, B3, C2
Answer  Explanation  Related Ques

ANSWER: A2, B3, C1

Explanation:
The type of waveform generation by an oscillator totally depends on components used in the circuit. Hence, they can be sinusoidal if RC components are used while they can be square if LC components are used & even they can be saw-tooth or triangular if crystal oscillator is used. Crystal Oscillators are stable to maximum extent as compared to that of RC & LC oscillators due to higher figure of merit (Q). However, crystal & LC oscillators find their applications in generation of high frequency signals while RC oscillators are intended for audio-frequency applications.


29)   What are the diodes (D1 & D2) used in comparator circuit usually refer to?

a. Clip Diodes
b. Clamp Diodes
c. PIN Diodes
d. Fast Recovery Diodes
Answer  Explanation  Related Ques

ANSWER: Clamp Diodes

Explanation:
Comparator is a circuit which performs comparison between the signal voltage on one input of Op-amp with reference voltage on another input. The arrangement of diodes in comparator circuit is in such a way that they play a cardinal role in protecting Op-amp from getting damage due to excess of input voltage. These diodes intentionally undergoes clamping of difference input voltage to 0.7 or -0.7 volts. However, these diodes are also called as 'Clamp Diodes'.


30)   In which type of oscillator, the output frequency is dependent on the amplitude of input voltage?

a. Quadrature Oscillator
b. Voltage Controlled Oscillator
c. Wein-bridge Oscillator
d. Phase-Shift Oscillator
Answer  Explanation  Related Ques

ANSWER: Voltage Controlled Oscillator

Explanation:
Generally, the time constant helps in determining the frequency of oscillation in any oscillator. But, in some of the applications like Frequency Modulation (FM), Frequency Shift Keying (FSK) where the frequency needs to be controlled by input voltage. This input voltage performs the functionality of controlling voltage level & hence, precisely referred as 'Control Voltage'. This entire functionality is undertaken by Voltage -Controlled Oscillator (VCO). Another name of VCO is Voltage to frequency converter.
For e.g. Signetics NE/SE 566 VCO generates the triangular as well as square wave outputs simultaneously as a function of an input voltage. VCO are applicable in conversion of low-frequency signals into audio frequency ranges especially in bio-medical applications EEG (electroencephalograms) & ECG (electrocardiograms).


31)   A basic generalized form of comparator is ______.

a. Zero-Crossing Detector
b. Sine to Square Wave Generator
c. Both a & b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Both a & b

Explanation:
The comparator can be configured to be useful in the form of Zero-Crossing Detector by just adjusting reference voltage to zero. There is sometimes possibility that low frequency signal may consume some more time to cross zero volt because of which output voltage cannot switch over instantaneously from one saturation region to another. Also, the noise at the op-amp input terminals may fluctuate the output between positive & negative (+Vsat & -Vsat) saturation voltages. Hence, both the shortcomings can be resolved by using positive or (regenerative) feedback.


32)   Hysteresis Phenomenon can be specifically exhibited in ______.

a. Positive Feedback Comparator
b. Negative Feedback Comparator
c. Both a & b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Positive Feedback Comparator

Explanation:
Hysteresis phenomenon is a dead-band condition where the output switches from +Vsat to -Vsat whenever input value becomes greater than the upper threshold voltage. Thus, when the input value falls below lower threshold voltage, then the output gets returned to its original position or state +Vsat. Therefore, hysteresis can be evaluated as a difference of upper threshold voltage (Vut) and lower threshold voltage (Vlt.). The most probabilistic approach of hysteresis occurrence can be observed in the comparators with positive (or regenerative) feedback. The significant advantage of hysteresis is that it increases the speed of operation of the comparator.


33)   The interval between application of an input step function & the time when the output crosses the value of logic threshold voltage of comparator is nothing but ______.

a. Strobe Release Time
b. Response Time
c. Settling Time
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Response Time

Explanation:
Typical electrical parameters of comparator include positive & negative output levels, strobe current & strobe release time, response time & saturation voltage. Thus, the interval between input step function & the duration of crossing logic threshold voltage at the output gives the conceptual idea of response time. On the other hand, the time required for rising the logic threshold voltage at the output after the driving session of strobe terminal is conducted from zero to one logic level. Eventually, the parameter of settling time is totally not involved in comparators.


34)   Which among the following is not an application of digital to analog converter?

a. Microcomputer Interfacing
b. Microprocessor Interfacing
c. Programmable Power supply
d. CRT graphics
Answer  Explanation  Related Ques

ANSWER: Microprocessor Interfacing

Explanation:
Microprocessor interfacing is an application of ADCs while all the remaining applications like microcomputer interfacing, programmable power supply & CRT graphics are the applications concerned to digital to analog converters in accordance to their functionalities.


35)   Which of the following key specifications are essential for the selection of digital to analog converter from application point of view?

a. Response time
b. Conversion time
c. Resolution & Settling time
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Resolution & Settling time

Explanation:
By taking into consideration the approach of application point of view, selection of an efficient digital to analog converters must have good specifications in terms of resolution, linearity or non-linearity of error, Gain & offset errors along with the settling time. Resolution specifies the number of input bits with the valuation in the form of least significant bit (LSB) whereas the settling time implies the requirement of time for DAC output to settle down between positive or negative ½ LSB of the final value of digital input (which is generally zero to full scale). However, response & conversion time are not the valid specifications for DAC selection since they are of significant importance in ADC.


36)   Which condition approves to be valid in case of reference voltage for the determination of clipping level?

a. Reference voltage must be less than input voltage
b. Reference voltage must be greater than input voltage
c. Reference voltage must be less than output voltage
d. Reference voltage must be greater than output voltage
Answer  Explanation  Related Ques

ANSWER: Reference voltage must be less than input voltage

Explanation:
Generation of clipping circuit using op-amp & rectifier diode is possible where the op-amp act as a voltage follower with diode in a feedback path. Since clipping circuit eliminates the positive parts of input signal, so the the value of reference voltage helps in determining the clipping level. Therefore, the voltage difference 'Vref' must be smaller than input voltage. When Vin Vref, then reference voltage is higher at the negative input as compared to that of the positive input.


37)   Which among the following is a military grade op-amp IC?

a. IC 555
b. IC LF 398
c. IC LM 117
d. IC 741
Answer  Explanation  Related Ques

ANSWER: IC 741

Explanation:
Op-amp ICs varying in the version of 741 are highly approved or sanctioned for military grade since the temperature range lies within -55° to 125°C. So, as the temperature level range display variations, the op-amp IC741 are further sub-categorized under the series of 741C, 741A & 741E & so on. Besides these, 741S & 741SC are recommended for military as well as commercial aspects due to high slew rate. Other ICs mentioned in the question are only applicable to certain specific sort of applications other than the military ones. Apart from these versions, IC 555 are widely applicable in timers, oscillators & pulse generators. IC LF 398 forms a leading part of sample & hold circuit while IC LM117 can be used as a switching regulator & also provides full overload protection to other ICs.


38)   Which Op-amp IC possessed the potential to tackle & overcome the drawbacks of first generation Op-amps?

a. μ A702
b. μ A709
c. μ A741
d. MC1537
Answer  Explanation  Related Ques

ANSWER: μ A741

Explanation:
The inceptional phase of first generation was initiated with the utility of IC op-amp 709. Several drawbacks related to performance characteristics were highlighted like no protection to short circuits, latch-up problem and absence of external frequency-compensating network for stable operation. All these major shortcomings were tackled by an internally compensated op-amp IC741 which had a provision of short-circuit protection, absence of latch-up problem & highly stable & proficient at the operational level. Hence, it is also regarded as 'Second-generation Op-amp'.


39)   Which techniques are adopted for the purpose of inductor designing in switching regulators?

a. Silicon Steel EI butt stacks
b. Ferrite EI, U & toroid cores
c. Powdered permalloy toroids
d. All of the above
Answer  Explanation  Related Ques

ANSWER: All of the above

Explanation:
Silicon steel EI butt stack method shows better permeability & high flux density along with the simplicity in construction phase. So, it is wide used in low-voltage switching regulators. Ferrite EI, U & toroid cores exhibits lower performance in the aspects of permeability, high temperature & expensive to greater extent. Powdered permalloy toroids possess are highly permeable with lower values of leakage inductance & losses. Due to this, they offer maximum stability & predictability but are very expensive similar to that of ferrite EI, U & toroid cores. However, all these mechanisms are adopted as per the requirement of desired application of switching regulator.


40)   Match the following pairs : Manufacturers IC Designations

a. Texas Instruments -------------------------------------- 1.  CA 3741
b. Signetics ----------------------------------------------------- 2.  SN52741
c. RCA ------------------------------------------------------------ 3.  LM741
d. National Semiconductor ------------------------------ 4.  N5741


a. A1, B2, C3, D4
b. A2, B3, C4, D1
c. A3, B4, C2, D1
d. A2, B4, C1, D3
Answer  Explanation  Related Ques

ANSWER: A2, B4, C1, D3

Explanation:
Corresponding to the manufacturers own productivity of ICs, they also go for the production of one another's renowned ICs. Thus, manufacturers generally holds the original type number in their own IC designation. For an instance, Op-amp 741 is originally developed by Fairchild but it also gets manufactured by different number of manufacturers under the category of their own designations. The pairs mentioned in the question clarifies this conceptual notion in the form of an illustration where the manufactures & their associated IC designations are mentioned.