MAHA SET 2015 Question Paper 2 Electronic Science

Test Booklet No.
F
ELECTRONIC SCIENCE
Signature and Name of Invigilator Seat No.
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(Name) ................................................ OMR Sheet No.
AUG - 38215 (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
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A B D
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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.

3. The biasing circuit which gives most
1. If the pn-junction is abrupt, the
stable operating point is :
capacitance varies as :
(A) base bias

(A) Square root of reverse bias (B) collector to base bias

(C) voltage divider bias
(B) Cube root of reverse bias
(D) emitter feedback bias
(C) Square root reverse current
4. FET is used as a buffer in

(D) Square of reverse bias measuring instruments, receivers
since it has :
2. Which of the following diode is
(A) high input impedance and low
referred as hot carrier diode ? output impedance

(B) high input impedance and high
(A) Schottky
output impedance
(B) Step recovery (C) low input impedance and low
output impedance
(C) Varactor
(D) low input impedance and high
(D) Zener output impedance

3 [P.T.O.

5. Tunnel diode exhibits : 7. The Fourier transform of a delta

(A) Linear resistor function is :

(B) Current dependent resistor (A) infinite flat band

(C) Voltage dependent resistor (B) a delta function

(D) Non-linear resistor (C) a finite width Gaussian

6. According to the Thevenin’s (D) a large band with notch

theorem any two terminal linear
8. A pole on the +ve imaginary
network can be replaced by a
axis inside ROC of the S-plot
generator equal to the open circuit
represents :
voltage between the terminals in

series : (A) decaying amplitude without

oscillations
(A) with the input impedance

(B) increasing amplitude without
(B) with parallel combination of

input and output impedance oscillations

(C) with output impedance as seen (C) constant oscillation amplitude

at this port (D) increasing amplitude with

(D) with shorted output oscillations

4

9. When two 2 port networks are 11. IC 7815 is capable of outputting :

connected in parallel it is convenient (A) +15 volts/1 A at full load

to use : (B) –15 volts/1 A at full load

(C) ±15 volts/1 A at full load
(A) open circuit impedance

(D) +12 volts/1 A at full load
parameters

12. In the practical differentiation
(B) short circuit impedance
circuit shown :
parameters

(C) transmission parameters

(D) inverse hybrid parameters

10. In a bandpass filter the shunt

element is :

(A) C1 cuts off high frequency noise
(A) capacitive
(B) R1 cuts off low frequency noise
(B) inductive
(C) R 1 , Cf form the basic

(C) series combination of L & C differentiation elements

(D) shunt combination of L & C (D) Cf ensures stable operation

5 [P.T.O.

13. The Barkhausen criterion for 15. The frequency of the output of

getting sustained oscillations
Bistable multivibrator is :

is A :
(A) twice the input frequency
(A) = Unity

(B) thrice the input frequency
(B) Unity

(C) half the input frequency
(C) < Unity

(D) = Zero (D) equal to the input frequency

14. Colpitts and Hartley oscillators 16. The minimum number of flip-flops

belong to a general class of required to construct a mod-75

oscillators that use ........................
counter is :

feedback.
(A) 5
(A) Voltage shunt

(B) 6
(B) Current series

(C) 7
(C) Voltage series

(D) Current shunt (D) 8

6

19. Gate ECL has the following
17. The following Boolean expression
disadvantage :

ABC + AB + ABC + A (A) High power dissipation

(B) Low speed of operation
can be simplified to :
(C) Low noise margin
(A) B
(D) High voltage supply required

(B) C 20. Simplification of AB + AB + AB will

lead to :
(C) A
(A) A

(D) 1 (B) A + B

(C) A + B
18. Schottky TTL gate modifies the
(D) A + B

following performance : 21. Which of the following status signals

is most important in handling
(A) Power handling capacity
external memory of 8051 ?

(B) Reduce input capacitance (A) IO/M

(B) ALE
(C) Reduce saturation charges
(C) EA

(D) Packing density (D) RESET

7 [P.T.O.

22. For interfacing a seven segment 24. Identify the instruction among the

display and a matrix keyboard
following, which supports register
to a 8085 microprocessor/8051
indirect addressing ?
microcontroller which of the

following peripheral chip is generally (A) ADD A

used ?
(B) MVI A, 2356H

(A) 8155
(C) AND A, M
(B) 8253

(D) XRA A
(C) 8259

(D) 8279 25. 8085, 8051 and 8086 have ............,

23. On chip code memory in case of ............, ............ wide data bus

microcontrollers with ISP support respectively.

is generally :
(A) 8, 16, 16
(A) EPROM
(B) 16, 8, 8
(B) SRAM

(C) 8, 8, 8
(C) EEPROM

(D) DRAM (D) 8, 8, 16

8

26. While opening a file the filename 28. How many times the following C

string is assigned to a : program loop will be executed ?

(A) Integer # include<stdio.h>

(B) File pointer int main( )

(C) Function {

int i = 0;
(D) Structure

for( ; ; )
27. Which of the following header file

must be included for drawing an printf(“%d”, i);

electronic circuit diagram using C return 0

program ? }

(A) stdio.h (A) infinite times

(B) graphics.h (B) 0 time

(C) video.h (C) 1 time

(D) math.h (D) 10 times

9 [P.T.O.

29. What will be output of the following 30. In C++, a declaration ................... the

C program ? program.

# include<stdio.h>
(A) must appear at the beginning

# include<conio.h> of

void main( )
(B) must appear at the end of

{
(C) must appear before # include
enum cc{Black, Brown, Red,
directive within
Orange, Yellow,
(D) may appear anywhere within
Green, Blue, Violet,

Gray, White}; 31. A transmission line with Z0 = 100

clrscr( ); is to be terminated in a load

of Z1 = 900 . The matching /4
printf(“%d”, Green);
transformer must have characteristic
getch( );
impedance of :
}
(A) 100
(A) 4

(B) 900
(B) Yellow

(C) 5 (C) 147

(D) Green (D) 300

10

32. The electromagnetic wave in free 35. The reflex klystron is a form of
space is of the type : klystron oscillator :

(A) TM (A) that requires two resonant

(B) TE cavities

(C) TEM (B) that is essentially a high-power

(D) Longitudinal device

33. In a directional coupler, ideally, the (C) where there is no bunching of

power coupled in the backward electrons

direction should be :
(D) that requires only a single
(A) 0 resonant cavity

(B) 36. 3 db points on the frequency

(C) Same as that at the input response curve of a voltage amplifier

(D) 1 are the ones at which voltage gain

reduces to :
34. In transmission line problems,

matching means simply terminating (A) unity

the line in ......................... impedance. (B) zero

(A) highest possible short circuit
(C) 1 2 of its middle frequency
(B) highest possible open circuit value

(C) its characteristic (D) 1/2 of its middle frequency

(D) short circuit value

11 [P.T.O.

37. In a superheterodyne radio 39. What is the primary function of
receiver : multiplexing ?

(A) the local oscillator frequency is (A) to reduce the bandwidth of a
made higher than the incoming signal
signal frequency
(B) to allow a number of signals to
(B) the local oscillator frequency is
make use of a single
made lower than the incoming
communications channel
signal frequency
(C) to match the frequency range
(C) the local oscillator frequency is
of a signal to a particular
made equal to the incoming
channel
signal frequency
(D) to select one radio channel
(D) the local oscillator frequency
from a wide range of
can be higher or lower than the
transmitted channels
incoming signal frequency
40. Which of the following is used to
38. A digital transmission has an
provide tracking between RF
error probability of 1 × 10–5 and
amplifier and local oscillator stages
is 1 × 108 bits long. Its expected
of the receiver ?
number of error bits is :

(A) 1 × 103 (A) Variable tuning inductor

(B) 1 × 105 (B) Ganged tuning inductor

(C) 1 × 104 (C) Variable capacitor

(D) 1 × 108 (D) Variable preset

12

41. A UJT has :
44. The following material is not suitable

(A) Anode, cathode and gate
for LED :
(B) Two anodes and one gate

(C) Emitter, base and collector (A) Si

(D) One emitter and two bases
(B) GaAs

42. A silicon controlled switch is :
(C) InGaAs
(A) an unilateral device with a

gate
(D) GaAsP

(B) an unilateral device with two
45. Gas lasers are not preferred
gates

(C) a bidirectional device for optical fiber communication

(D) a bilateral device with two
because of :
gates

(A) Low directionality
43. An SCR is :

(A) 3 layer, tri-junction device (B) High numerical aperture

(B) 3 layer, four-junction device
(C) Physical compatibility
(C) 4 layer, tri-junction device

(D) 4 layer, 4-junction device (D) Reliability issues

13 [P.T.O.

46. For catching glitches in a event, 49. The characteristic equation of a
the important parameter for a
feedback control system is :
DSO is :
s3 + ks2 + 5s + 10 = 0
(A) Number of A/D channels

(B) Vertical resolution For the system to be critically stable

(C) Real time bandwidth the value of k should be :

(D) Memory length of DSO (A) 1

47. Gauge factor of a strain gauge (B) 2
depends upon :
(C) 3
(A) Young’s modulus
(D) 4
(B) Poisson’s ratio

(C) Length of the strain gauge 50. PID controller is a controller

(D) Thickness of the strain gauge with :

48. The difference between spectrometer (A) open loop control
and spectrophotometer is that, the
(B) three terms having adjustable
spectrophotometer uses :
gain for each term
(A) Optical array detector
(C) three terms with adjustable
(B) High resolution gratting
gain for proportional term only
(C) White light source

(D) Thermal detectors (D) ability for feed forward control

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ROUGH WORK

15 [P.T.O.

ROUGH WORK

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