MAHA SET 2018 Question Paper 2 Electronic Science

Test Booklet Code & Serial No.
A
ELECTRONIC SCIENCE
Signature and Name of Invigilator Seat No.
1. (Signature) ......................................... (In figures as in Admit Card)
(Name) ................................................ Seat No. ..............................................................
2. (Signature) ......................................... (In words)

(Name) ................................................ OMR Sheet No.
JAN - 38218 (To be filled by the Candidate)
Time Allowed : 1¼ Hours] [Maximum Marks : 100
Number of Pages in this Booklet : 16 Number of Questions in this Booklet : 50
Instructions for the Candidates
1. Write your Seat No. and OMR Sheet No. in the space provided 1.
on the top of this page.
2. This paper consists of 50 objective type questions. Each question
will carry two marks. All questions of Paper-II will be compulsory, 2.
covering entire syllabus (including all electives, without options).
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A B D
(C)
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12. There is no negative marking for incorrect answers. 12.

2

Electronic Science
Paper II
Time Allowed : 75 Minutes] [Maximum Marks : 100

Note : This Paper contains Fifty (50) multiple choice questions. Each question

carries Two (2) marks. Attempt All questions.

1. The potential barrier in a pn - 3. Most of the majority carriers from
junction is formed after stabilizing
the emitter :
the carrier transport. Under this
condition : (A) Recombine in the base

(A) Drift Current > Diffusion
(B) Recombine in the emitter
Current
(C) Pass through the base region to
(B) Drift Current < Diffusion
Current the collector

(C) Drift Current = Diffusion (D) Remain in the base
Current
4. An enhancement type, basically
(D) Drift Current >> Diffusion
Current termed as normally OFF N-

2. In the breakdown region, a Zener MOSFET works only with :
diode behaves like a..............source.
(A) Large positive gate voltage
(A) Constant voltage
(B) Large negative gate voltage
(B) Constant current

(C) Constant current sink (C) Large positive drain voltage

(D) Constant power (D) Large negative drain voltage

3 [P.T.O.

5. The process of selectively removing 7. The voltage V in the circuit shown

certain protective regions from the in the following figure is :

surface of a substrate is known

as :

(A) Epitaxy

(B) Lithography
(A) 10 V
(C) Metalization (B) 15 V

(D) Bonding (C) 5 V
(D) 3 V
6. Refer to the network shown in the 8. In the graph shown in the following
following figure : figure, the number of trees (P) and
the number of cut sets (Q) are :

The tie set matrix is :

(A) [1, 1]

(B) [4, 4] (A) P = 2, Q = 2
(B) P = 2, Q = 6
(C) [10, 25]
(C) P = 4, Q = 6
(D) [10, 4]
(D) P = 4, Q = 10

4

9. The Fourier series of a real periodic 11. Calculate the cut-off frequency of an
function has only :
OP-Amp based first order low pass
P : cosine terms if it is even
filter for R = 2·5 k and C = 0·05
Q : sine terms if it is odd
F.
R : cosine terms if it is odd
(A) 1·273 kHz
S : sine terms if it is even

Which of the above statements are (B) 12·73 kHz

correct ?
(C) 127·3 kHz
(A) P and S
(D) 127·3 Hz
(B) P and Q
12. Current sense resistor in a voltage
(C) P and R

regulator circuit is placed at :
(D) Q and R

10. The trigonometric Fourier series of (A) Across the pass transistor

a periodic time function can have
(B) Parallel to the load resistor
only :

(A) cosine terms (C) In series with emitter of pass

(B) sine terms transistor

(C) DC and cosine terms (D) In series with the collector of

(D) cosine and sine terms pass transistor

5 [P.T.O.

13. According to transfer characteristics 15. The output of a rectifier circuit

of XLL the phase error between without filter is :

VCO output and incoming signal
(A) 50 Hz AC
must be maintained between.............
(B) Smooth DC
in order to maintain a lock.

(C) Pulsating DC
(A) 0 and

(D) 25 Hz DC
(B) 0 and /2

16. For a NAND gate having two inputs
(C) 0 and 2

the output is low (0) only :
(D) and 2

(A) When both inputs are high
14. Voltage regulator LM 723 is best

suited for voltage regulation : (B) When both inputs are low

(A) 0 to 40 V (C) When any one of the inputs is

(B) 0 to 27 V high and other is low

(C) 9·5 to 40 V (D) When a specified input is high

(D) 2 to 37 V and other is low

6

17. Synchronous counters are different 19. Boolean algebra does not apply to

from ripple counters in which clock
the relation :

pulses are applied ?
(A) 0 + 0 = 0
(A) In cascade manner to all flip-

(B) 0 + 1 = 1
flops

(B) To the inputs of all flip-flops (C) 1 + 1 = 1

(C) To the even number of flip-flops (D) 0 – 1 = 1

(D) To the odd number of flip-flops
20. Commutative law for addition and

18. An OR gate in positive logic
multiplication holds good for :

functions as :
(A) OR gate only
(A) AND gate in Negative logic

(B) AND gate only
(B) NAND gate in Negative logic

(C) Both OR and AND gate
(C) NOR gate in Negative logic

(D) NOT gate in Negative logic (D) NOT gate only

7 [P.T.O.

23. IO/M signal is generally used for
21. What is the order decided by a

distinguishing between :
processor or the CPU of a controller
(A) Data entry from keyboard and
to execute an instruction ?
memory device

(A) Decode, fetch, execute
(B) Memory mapped IOs and IO

(B) Execute, fetch, decode mapped IOs

(C) Serial and parallel
(C) Fetch, execute, decode
communication

(D) Fetch, decode, execute
(D) Synchronous and asynchronous

22. An internal RAM memory of the data transfers

8051 is : 24. When PUSH PSW instruction is

executed, the stack pointer :
(A) 32 bytes
(A) Decrements by 1
(B) 64 bytes
(B) Increments by 1

(C) 128 bytes
(C) Increments by 2

(D) 64 k bytes (D) Decrements by 2

8

25. The width of the instruction queue/ 28. In C++/C operators such as.............

pipeline in 8086 microprocessor is : cannot be overloaded.

(A) 4-bytes (A) +

(B) + +
(B) 6-bytes
(C) : :
(C) 8-bytes
(D) = =
(D) 2-bytes
29. The first index number in an array
26. In C++ .................. operator is used
starts with................and the index
for Dynamic memory allocation. number of an array of size n will

(A) Scope resolution be :

(B) Conditional (A) 0, n – 1

(B) 1, n – 1
(C) New
(C) 0, n
(D) Membership access
(D) 1, n
27. The.................objects have values
30. To overload an operator..................
that can be tested for various error
keyword must be used along with
conditions.
the operator to be overloaded.
(A) osstream
(A) Over
(B) ofstream
(B) Overload
(C) stream (C) Void

(D) ifstream (D) Operator

9 [P.T.O.

31. Ohm’s law when applied to 33. A transmission line when

electromagnetic phenomenon gives terminated in a certain load has a

the following expression : reflection coefficient of 1/3. What

will be the VSWR ?
(A) J E

(A) 1
(B) V = IR

(B) 2
(C) JE

(C) 2·5
(D) E J

(D) 3
32. What is the amplitude of the

displacement current density in 34. In which of the following devices

A/m2 inside a capacitor where D = mobility of the electrons decreases

3 × 10–7 sin (6 × 107t – 0·35x) aˆ z as the electric field strength

C/m2 and r = 100.
increases over a certain range ?

(A) 3 A/m2 (A) Si

(B) 6 A/m2 (B) Ge

(C) 9 A/m2 (C) GaAs

(D) 18 A/m2 (D) Metals

10

35. A Gunn diode of thickness 7 m has 37. The maximum dynamic range for a

a drift velocity of 1 × 105 m/s, find linear PCM system using 16-bit

the transit time of an electron : quantizing :

(A) 98·08 dB
(A) 7 × 10–11 s

(B) 49·04 dB
(B) 7 × 10–1 s

(C) 32 dB
(C) 7 × 10–6 s

(D) 16 dB
(D) 7 s

38. A modular transmits symbols, each
36. A signal x1(t) is bandlimited to 2 kHz
of which has sixty four different
while x2(t) is bandlimited to 3 kHz.
possible states, 10,000 times per
The Nyquist sampling rate for signal
second. The baud rate and bit rate
x1(t) x2(t) shall be :
are :

(A) 10 kHz
(A) 10 kbaud, 60 kb/s

(B) 4 kHz
(B) 10 kbaud, 30 kb/s

(C) 6 kHz (C) 0·64 Mbaud, 60 kb/s

(D) 12 kHz (D) 10 kbaud, 10 kb/s

11 [P.T.O.

39. Choose the correct statement : 41. TRIAC is a bidirectional power

(A) Narrowband FM offers better electronic device which contains :

SNR than AM (A) Two BJTs connected in parallel

(B) Narrowband FM offers poor (B) Two pn junction diodes

SNR than AM connected in series

(C) Narrowband FM offers no (C) Two SCRs connected in reverse

improvement in SNR over AM parallel

(D) Narrowband FM augments (D) Two SCRs connected in series

SNR as compared to AM 42. In a step down chopper using pulse

40. In order to transmit at 4·8 kbps over width modulation, TON = 9 × 10–3 s

a channel with 3·2 kHz bandwidth, and TOFF = 1 × 10–3 s. The chopping

which would be most suitable ? frequency is :

(A) BPSK (A) 200 Hz

(B) QPSK (B) 1000 Hz

(C) 8-PSK (C) 500 Hz

(D) 16-PSK (D) 100 Hz

12

45. Molecular size of SiO2 in optical
43. Colour of light emitted by LED
fiber leads to the following :
depends on :
(A) Absorption

(A) Reflector used in construction (B) Scattering

(C) Pulse dispersion
(B) Magnitude of forward bias
(D) Strain

(C) Energy band gap
46. Strain gauge is a/an :

(D) Forward current (A) Active device and converts

mechanical displacement into a

44. Which is the major cause of change of resistance.

dispersion in multimode step index (B) Passive device and converts

electrical displacement into a
optical fiber ?
change of resistance.

(A) Intermodal (C) Passive device and converts

mechanical displacement into a
(B) Material
change of resistance.

(D) Active device and converts
(C) Wave guide
electrical displacement into a

(D) Chromatic change of resistance.

13 [P.T.O.

47. Which of the following are 49. For the system shown in the

following figures, the damping ratio
integrating instruments ?
of closed loop poles is :
(A) Ammeters

(B) Voltmeters

(C) Wattmeters
(A) 1·5
(D) Ampere-hour and Watt-hour

meters (B) 1

48. A piezoelectric force transducer has (C) 0·5

a charge sensitivity of 20 pC/N. It
(D) 0·25
is connected to a charge amplifier
50. A PI controller increases :
and overall gain of transducer and
(A) Type of system by 1
amplifier is 50 mV/N. The gain of

the amplifier is : (B) Order of system by 1

(A) 1 mV/pC (C) Type and order of system

(B) 1·5 mV/pC decreases by 1

(C) 2·5 mV/pC (D) Type and order of system

(D) 4 mV/pC increases by 1

14

ROUGH WORK

15 [P.T.O.

ROUGH WORK

16