LECTURER IN ELECTRONICS ENGINEERING- NCA- TECHNICAL EDUCATION
PROVISIONAL ANSWER KEY
Question Paper Code: 52/2017/OL
Category Code: 318/2015
Exam: Lecturer in Electronics Engineering(NCA)
Medium of Question: English
Date of Test 04-07-2017
Department Technical Education
Alphacode A
Question1:-Name the person who was greatly influenced by the radical reformist journal of Cairo, the Al-Manar
A:-Moulana Abdul Kalam Azad
B:-Sir Sayyid Ahmed Khan
C:-Mohammed Abdul Rahman
D:-Vakkom Moulavi
Correct Answer:- Option-D
Question2:-Which among the following organization was founded in 1914 ?
A:-Samathwa Samajam
B:-Nair Service Society
C:-SNDP Yogam
D:-Yogaskhema Sabha
Correct Answer:- Option-B
Question3:-Which one of the following is not written by Ponkunnam Varkey ?
A:-Vikarasadanam
B:-Nivedanam
C:-Aniyara
D:-Kudumbini
Correct Answer:- Option-D
Question4:-Name the first editor of Swadeshabhimani
A:-Ramakrishna Pillai
B:-P. Krishna Pillai
C:-K. P. Kesava Menon
D:-C. P. Govinda Pillai
Correct Answer:- Option-D
Question5:-Vagbhadanandha was the main disciple of
A:-Sree Narayanaguru
B:-Chattampi Swamikal
C:-Brahmananda Sivayogi
D:-V. T Bhattathiripad
Correct Answer:- Option-C
Question6:-Monetary Museum of Reserve Bank of India is situated at
A:-Kolkata
B:-Mumbai
C:-Bengaluru
D:-Delhi
Correct Answer:- Option-B
Question7:-Recently Thousand history buffs gathered in Czech Republic to re-enact the Battle of Austerlitz. Name the ruler
related with this Battle.
A:-Napoleon
B:-Henry V
C:-Louis XVI
D:-Sir Nicholas II
Correct Answer:- Option-A
Question8:-India made the Howitzer Artillery gun deal with
A:-France
B:-USA
C:-Russia
D:-Israel
Correct Answer:- Option-B
Question9:-Central Road Research Institute was established in
A:-1952
B:-1948
C:-1956
D:-1964
Correct Answer:- Option-A
Question10:-Who directed the Hindi filim ‘Ae Dil Hai Mushkil’
A:-Apoorva Mehta
B:-Mukesh Bhat
C:-Karan Johar
D:-Yash Chopra
Correct Answer:- Option-C
Question11:-The minority carrier current in a semiconductor diode is largely a function of
A:-Amount of doping
B:-Temperature
C:-Forward bias voltage
D:-Reverse bias voltage
Correct Answer:- Option-B
Question12:-When the transistor is in high saturation, the biasing condition of base emitter BE and collector base CB
junction is
A:-BE forward biased, CE reverse biased
B:-BE reversed biased, CE forward biased
C:-BE forward biased, CE forward biased
D:-BE reverse biased, CE reverse biased
Correct Answer:- Option-C
Question13:-Memory that losses its contents when power is lost is
A:-Non volatile
B:-Volatile
C:-Flash memory
D:-Static memory
Correct Answer:- Option-B
Question14:-In a bridge rectifier, if `V_m` is the peak voltage across the secondary of transformer, the maximum voltage
coming across each reverse biased diode is
A:-`V_m`/2
B:-`V_m`/`sqrt(2)`
C:-`2V_m`
D:-`V_m`
Correct Answer:- Option-D
Question15:-The main advantage of CMOS is its
A:-Low power consumption
B:-High power rating
C:-Small signal operation
D:-Fast switching capability
Correct Answer:- Option-A
Question16:-The space-charge region contains charges that are
A:-Mostly majority carriers
B:-Mostly minority carriers
C:-Fixed donor and acceptor ions
D:-Mobile donor and acceptor ions
Correct Answer:- Option-C
Question17:-The microwave tube that uses buncher and catcher cavities is
A:-Magnetron
B:-Klystron
C:-Reflex Klystron
D:-Travelling wave tube
Correct Answer:- Option-B
Question18:-Which of the following has same probability of error ?
A:-BPSK and QAM
B:-BPSK and ASK
C:-BPSK and QPSK
D:-BPSK and PAM
Correct Answer:- Option-D
Question19:-The negative resistance of the tunnel diode occurs when the bias voltage is
A:-Between the peak and valley voltages
B:-Above the valley voltage
C:-Below the peak voltage
D:-In the reverse direction
Correct Answer:- Option-A
Question20:-In an RC differentiator, the condition for differentiation is
A:-RC >> 0.16T
B:-RC << 0.16T
C:-RC >> T/0.16
D:-RC << T/0.16
Correct Answer:- Option-B
Question21:-For an input pulse train of clock period T, the delay produced by an n stage shift register is
A:-2nT
B:-nT
C:-(n + 1)T
D:-(n - 1)T
Correct Answer:- Option-C
Question22:-An n-channel JFET has `I_(DSS)` = 1 mA and `V_(P)` = -5 V. Its maximum transconductance is
A:-0.4 millimho
B:-0.1 millimho
C:-1.0 millimho
D:-4.0 millimho
Correct Answer:- Option-A
Question23:-For thyristors, pulse triggering is preferred to dc triggering because
A:-Gate dissipation is low
B:-Pulse system is simpler
C:-Triggering system is required for a very short duration
D:-All of these
Correct Answer:- Option-D
Question24:-If an amplifier with a gain of −1000 and feedback of β=−0.1 had a gain change of 20% due to temperature, the
change in gain of the feedback amplifier would be
A:-0.2%
B:-5%
C:-10%
D:-0.01%
Correct Answer:- Option-A
Question25:-The sensitivity of a multimeter is given in
A:-Ω
B:-KΩ/V
C:-Amperes
D:-V/KΩ
Correct Answer:- Option-B
Question26:-A superheterodyne radio receiver with an intermediate frequency of 455 KHz is tunded to a station operating at
1200 KHz. The associated image frequency is
A:-55 KHz
B:-1110 KHz
C:-2110 KHz
D:-4220 KHz
Correct Answer:- Option-C
Question27:-The multivibrator circuit configuration that can be used to convert a sinusoidal input into a square wave output
is
A:-A stable multivibrator
B:-Monostable multivibrator
C:-Bistable multivibrator
D:-Schmitt trigger
Correct Answer:- Option-D
Question28:-A Yagi antenna in a horizontal plane produces
A:-A broadside pattern
B:-An endfire pattern
C:-A figure of eight pattern
D:-None of the above
Correct Answer:- Option-B
Question29:-A problem with class B push pull amplifier is that they usually suffer from
A:-Harmonic distortion
B:-Intermodulation distortion
C:-Cross-over distortion
D:-None of these
Correct Answer:- Option-C
Question30:-A 12 bit binary number has an accuracy equivalent to the decimal fraction
A:-1/1024
B:-1/2048
C:-1/6400
D:-1/4096
Correct Answer:- Option-D
Question31:-If a pulse train with a frequency of 10 KHz is applied to the trigger input of a bistable multivibrator, the
frequency of the output pulse train would be
A:-5KHz
B:-20 KHz
C:-10 KHz
D:-None of these
Correct Answer:- Option-A
Question32:-Six independent low pass signals of bandwith 3 W, W, W, 2W, 3W and 2W Hz are to be time division
multiplexed on a common channel using PAM. To achieve this, the minimum transmission bandwidth of the channel should
be __________ Hz.
A:-12W
B:-6W
C:-3W
D:-24 W
Correct Answer:- Option-A
Question33:-Class a amplifiers are characterised by
A:-Maximum efficiency and minimum distortion
B:-Minimum efficiency and maximum distortion
C:-Maximum efficiency and maximum distortion
D:-Minimum efficiency and minimum distortion
Correct Answer:- Option-D
Question34:-From cricuit design simplicity and economy point of view, one of the following configurations for a converter is
the best. Which is that ?
A:-Push-pull DC-DC converter using one transformer
B:-Ringing choke converter
C:-Push-pull converter using two transformers
D:-None of these
Correct Answer:- Option-B
Question35:-An op-amp is having is having an open loop gain of `10^(5)` and open loop upper cutoff frequency of 10 Hz. If
this op-amp is connected as an amplifier with a closed loop gain at 100, then the new upper cutoff frequency will be
A:-10 Hz
B:-100 Hz
C:-10 KHz
D:-100 KHz
Correct Answer:- Option-C
Question36:-An amplifier power level is changed from 8 Watts to 16 Watts, equivalent dB gains is
A:-2 dB
B:-3dB
C:-6 dB
D:-5 dB
Correct Answer:- Option-C
Question37:-Which of the following statements are correct for the basic transistor amplifier configurations
A:-CB amplifier has low input impedance and a low current gain
B:-CC amplifier has low output impedance and a low current gain
C:-CE amplifier has very poor voltage gain but very high input impedance
D:-none of the above
Correct Answer:- Option-A
Question38:-In antenna measurement using two aperture antennas of dimensions D1 and D2, minimum speparation
between the two should be (λ is free space wavelength of radiation uses)
A:-(D1 + D2)/(2λ)
B:-`(D1^2+D2^2)` /(λ)
C:-(`D1^2+D2^2)` /(8λ)
D:-`(D1^2+D2^2)` /2λ)
Correct Answer:- Option-B
Question39:-Compared to the junction transistor, FET
1) Has a larger gain banwidth product
2) Is less noisy
3) Has less input resistance
4) Has only the majority carrier flow
The correct statements are
A:-1, 3
B:-1, 2
C:-3, 4
D:-2, 4
Correct Answer:- Option-D
Question40:-How does 80386 change operation from real mode to protected mode ?
A:-By resetting MSB of CR1 contents
B:-By setting MSB of CR0 contents
C:-By setting MSB of CR1 contents
D:-By setting MSB of CR2 contents
Correct Answer:- Option-B
Question41:-A source follower (using a FET) usually has a voltage gain which is
A:-Slightly less than unity, but positive
B:-Greater than +1
C:-Exactly unity but negative
D:-About − 10
Correct Answer:- Option-A
Question42:-Which of the following logic family consumes the least amount of power ?
A:-`I^2` L
B:-ECL
C:-TTL
D:-CMOS
Correct Answer:- Option-D
Question43:-In a 100% amplitude modulated signal, the power in the lower sideband is : Assume carrier power to be 100
watts and modulation system to be SSBSC.
A:-50 watts
B:-100 watts
C:-25 watts
D:-None of these
Correct Answer:- Option-C
Question44:-A combinational logic circuit which is used to sen data coming from a source to two or more seperate
destinations is called as
A:-Demultiplexer
B:-Encoder
C:-Multiplier
D:-Decoder
Correct Answer:- Option-A
Question45:-The pinch off voltage of a JFET is 5V. Its cut off voltage is
A:-`(5.0)^(1/2)`V
B:-2.5 V
C:-`(5.0)^(3/2)V`
D:-5.0 V
Correct Answer:- Option-D
Question46:-A full wave rectifier uses two diodes, the internal resistance of each diode may be 20Ω each. The transformer
rms secondary voltage from centre tap to each of secondary is 50V and load resistance is 980 Ω. Find the mean load current
and rms value of load current.
A:-0.05/`sqrt(2)` , 0.05`pi`
B:-0.05`sqrt(2)` ``/`pi` , 0.05
C:-0.1`sqrt(2)` ` ` /`pi` ,0.05
D:-50`sqrt(2)`/`pi` , 50
Correct Answer:- Option-C
Question47:-The 2732 is a 4096 `xx` 8 EPROM. How many address lines does it have ?
A:-8
B:-12
C:-1600
D:-2732
Correct Answer:- Option-B
Question48:-A lamp is controlled from two positions A and B (eg : staircase circuit). The boolean expression for the above
circuit is
A:-
B:-
C:-
D:-
Correct Answer:- Option-B
Question49:-Most of the linear IC s are based on the two transistor differential amplifier because of its
A:-High CMRR
B:-High voltage gain
C:-High input resistance
D:-Input voltage dependent linear transfer characteristics
Correct Answer:- Option-A
Question50:-A speech signal occupying the bandwidth of 300 Hz to 3 KHz is converted into PCM format for use in digital
communication. If the sampling frequency is 8 KHz and each sample quantized into 256 levels, then the output bit rate will
be
A:-3 Kb/s
B:-8 Kb/s
C:-256 Kb/s
D:-64 Kb/s
Correct Answer:- Option-D
Question51:-A push pull inverter provides a
A:-Highly regulated output
B:-Constant DC output
C:-Square wave output
D:-None of these
Correct Answer:- Option-C
Question52:-When an antenna is placed in a vertical plane it will produce ?
A:-Circularly polarised waves
B:-Elliptically polarised waves
C:-Horizontally polarised waves
D:-Vertically polarised waves
Correct Answer:- Option-C
Question53:-The octal equivalent of decimal 324.781 is
A:-40.987
B:-540.781
C:-215.234
D:-504.771
Correct Answer:- Option-D
Question54:-In a travelling wave tube, the phase velocity of the axial components of the field of the slow wave structure is
kept
A:-Slightly less than the velocity of electrons
B:-Equal to the velocity of the electrons
C:-Slightly more than the velocity of electrons
D:-Equal to the velocity of light in free space
Correct Answer:- Option-B
Question55:-Address bus of 8086 contains
A:-20 lines
B:-32 lines
C:-16 lines
D:-24 lines
Correct Answer:- Option-A
Question56:-The propagation delay for ECL IC family is approximately
A:-2ns
B:-10ns
C:-25ns
D:-50ns
Correct Answer:- Option-A
Question57:-The pre-emphasis circuit is used
A:-After modulation
B:-To increase or emphasise the amplitude low frequency
C:-Prior to modulation
D:-None of these
Correct Answer:- Option-C
Question58:-A NAND circuit with positive logic will operate as
A:-AND with negative logic
B:-AND with negative logic
C:-OR with negative logic
D:-NOR with negative logic
Correct Answer:- Option-D
Question59:-The average on state current for an SCR is 20A for a conduction angle of 120°. The average on=state current
for 60° conduction angle will be
A:-20 A
B:-Less than 20 A
C:-10 A
D:-40 A
Correct Answer:- Option-B
Question60:-A switched mode power supply operating at 20 KHz to 100 KHz range uses _______ as the main switching
element.
A:-MOSFET
B:-Triac
C:-Thyristor
D:-UJT
Correct Answer:- Option-A
Question61:-The biggest disadvantage of CW Doppler radar is that
A:-It does not give the target position
B:-It does not give target velocity
C:-It does not give target range
D:-A transponder is required at the target
Correct Answer:- Option-C
Question62:-The field frequency of HDTV is
A:-15
B:-60
C:-30
D:-120
Correct Answer:- Option-B
Question63:-An NPN transistor has a beta frequency `f_beta` of 1 MHz, and emitter short circuit low frequency current gain
`beta_(0)` of 200. The unity gain frequency `f_(T)` and alpha cutoff frequency `f_(alpha)` respectively are
A:-199 MHz, 200 MHz
B:-200 MHz, 199 MHz
C:-201 MHz, 200 MHz
D:-200 MHz, 201 MHz
Correct Answer:- Option-D
Question64:-An opamp has a slew rate of 5V/μS. The largest sine wave output voltage possible at frequency of 1 MHZ is
A:-10π volts
B:-5 volts
C:-(5/π)volts
D:-(5/2π)volts
Correct Answer:- Option-D
Question65:-The number of comparisons carried out in a 5 bit flash type A/D converter is
A:-31
B:-32
C:-5
D:-3
Correct Answer:- Option-A
Question66:-A PLA can be used
A:-As a dynamic memory
B:-To realise a combinational logic
C:-As a microprocessor
D:-To realise a sequential logic
Correct Answer:- Option-B
Question67:-Hamming codes are used for error detection and correction. If the minimum hamming distance is m, then the
number of errors correctable is
A:-Equal to 2 m
B:-Equal to m
C:-Less than m/2
D:-Greater than m
Correct Answer:- Option-C
Question68:-Given that `W=e^(-i(2`Pi` /N)` , where N = 3. Then `F = W^N` can be computed as F =
A:-0
B:-1
C:-e
D:-−1
Correct Answer:- Option-B
Question69:-The code division multiple access technique is not used in satellite communication because of
A:-Wastage of power
B:-Wastage of baseband spectrum
C:-Increase in delay
D:-Complexity and unreliability of operation
Correct Answer:- Option-A
Question70:-Which of the following is introduced in the frequency sampling realization of the FIR filter ?
A:-Poles are more in number on unit circle
B:-Zeros are more in number on the unit circle
C:-Poles and zeros at equally spaced points on the unit circle
D:-None of the above
Correct Answer:- Option-C
Question71:-The number of LED display indicators in logic probes are
A:-1
B:-4
C:-1 or 2
D:-2
Correct Answer:- Option-D
Question72:-In a linear IC voltage, series pass transistor always operates in _________ region.
A:-Active
B:-Saturation
C:-Cutoff
D:-All of the above
Correct Answer:- Option-A
Question73:-The data rate of QPSK is ________ of BPSK.
A:-Thirce
B:-4 times
C:-Twice
D:-Same
Correct Answer:- Option-C
Question74:-Asymmetrical astable multivibrartor has R = 100Ω and C =0.1mF. The periodic time T is equal to
A:-138 mS
B:-69 mS
C:-6.9 mS
D:-13.8 mS
Correct Answer:- Option-D
Question75:-Bootstrap sweep circuit generally employs
A:-CE amplifier
B:-Emitter follower
C:-CB amplifier
D:-Tuned amplifier
Correct Answer:- Option-B
Question76:-If P=```[[1,0],[0,1]]` and Q=`[[0,1],[1,0]]` , then PQ is
A:-A null matrix
B:-An identity matrix
C:-A singular matrix
D:-A symmetric matrix
Correct Answer:- Option-D
Question77:-If P = `[[2,3],[5,7]]`, then `P^-1` =
A:-`[[-2,-3],[-5,-7]]`
B:-`[[7,-3],[-5,2]]`
C:-`[[-7,3],[5,-2]]`
D:-`[[2,-5],[-3,7]]`
Correct Answer:- Option-C
Question78:-The first three terms in the expansion of `(a+bx)^m` are 1, 6x and 16`x^2` respectively (`alpha` > 0, m is a
natural number). Then
A:-m = 9, b = `2/3`
B:-m = 2, b = 3
C:-m = 4, b = `3/2`
D:-m = 3, b = 2
Correct Answer:- Option-A
Question79:-The value of cot 1°+ cot 89° is
A:-0
B:-1
C:-`2/sin 2^o`
D:-None of these
Correct Answer:- Option-C
Question80:-In Δ ABC, the value of is
A:-−2 tan A sin B cos C
B:-0
C:-`tan^2` A
D:-tan A(tan A−2 sin B cos C)
Correct Answer:- Option-B
Question81:-The x-intercept of the line passing through the point (1, 1) and perpendicular to the line
x − 2y + 1 = 0 is
A:-`2/3`
B:-`(-2)/(3)`
C:-`3/2`
D:-`(-3)/(2)`
Correct Answer:- Option-C
Question82:-If , then the value of `lim_(x->0)“f(x)/x^2` is
A:-–2
B:-0
C:-1
D:-2
Correct Answer:- Option-B
Question83:-If x = a(cos `theta` −log cot `theta/2`) , y = a sin `theta`, then `dy/dx` =
A:-tan θ
B:-−tan `theta`
C:-cot `theta`
D:-−cot `theta`
Correct Answer:- Option-A
Question84:-The integral of ` “ `with respect to x is
A:-`tan(xe^(x))/((x+1)e^(x))`+C
B:-
sec`(xe^(x))“tan(xe^(x))+C`
C:-sec`(xe^(2))“+C`
D:-`tan(xe^(x))+C`
Correct Answer:- Option-D
Question85:-The slope of normal to a curve at any point (x, y) on it is `(-x)/((x+1)y)` . The equation of the curve is
A:-y = `Cxe^x`
B:-xy=`Ce^x`
C:-xy=`Ce^-x`
D:-`y^(2)=2[log(x+1)-x]+C`
Correct Answer:- Option-A
Question86:-The Coulomb is equal to charge on __________ electrons.
A:-1.602` xx` `10^-19`
B:-6.28 `xx` `10^18`
C:-1.67 `xx` `10^-27`
D:-6.18 `xx` `10^28`
Correct Answer:- Option-B
Question87:-The Ohm’s laws deals with the relation between
A:-Charge and capacity
B:-Capacity and p.d.
C:-Charge and resistance
D:-Current and p.d.
Correct Answer:- Option-D
Question88:-One kwh is equal to __________ kCal.
A:-860
B:-735.5
C:-36 `xx` `10^5`
D:-746
Correct Answer:- Option-A
Question89:-Resistivity is usually expressed in terms of
A:-ohm/°`^C`
B:-Moh
C:-Ohm meter
D:-Ohm/cm square
Correct Answer:- Option-C
Question90:-Three equal resistors are connected in series across an emf source, dissipate 60 W of power. What is the power
dissipated if the same resistors are connected in parallel ?
A:-270
B:-60
C:-20
D:-180
Correct Answer:- Option-B
Question91:-The main constituents of a Portland Cement is
A:-lime
B:-Alumina
C:-Iron Oxide
D:-Alkalies
Correct Answer:- Option-A
Question92:-The most commonly used bond for all wall thickness is
A:-Flemish bond
B:-English bond
C:-Stretching bond
D:-Heading bond
Correct Answer:- Option-B
Question93:-A line normal to the plumb line at all points is known as
A:-Horizontal line
B:-Vertical line
C:-Level line
D:-Line of the collimation
Correct Answer:- Option-C
Question94:-In a well-conditioned triangle, no angle should be less than
A:-30°
B:-45°
C:-60°
D:-90°
Correct Answer:- Option-A
Question95:-A fixed point of reference of known elevation is called
A:-Change point
B:-Station point
C:-Bench mark
D:-Datum
Correct Answer:- Option-C
Question96:-The part which controls the air fuel ratio in a petrol engine is
A:-Injector
B:-Carburettor
C:-Governor
D:-None of the above
Correct Answer:- Option-B
Question97:-In IC Engines the process of removing burnt gases from combustion chamber of cylinder is known as
A:-Supercharging
B:-Polymerisation
C:-Scavenging
D:-Detonation
Correct Answer:- Option-C
Question98:-The compression ratio of Diesel engine varies from
A:-15 to 25
B:-10 to 15
C:-6 to 10
D:-25 to 40
Correct Answer:- Option-A
Question99:-The purpose of moderator in a nuclear power plant is
A:-To moderate the radioactive pollution
B:-To control reaction
C:-To reduce temeprature
D:-To reduce the speed of fast moving neutrons
Correct Answer:- Option-D
Question100:-The differential is located between propeller shaft and the
A:-Clutch
B:-Engine
C:-Rear axle
D:-None of the above
Correct Answer:- Option-C
