MH SET 2013: 1 December, Paper III, Electronic Science
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Eelectronic Science
Paper III
Time Allowed : 2½ Hours] [Maximum Marks : 150
Note : This Paper contains Seventy Five (75) multiple choice questions, each
question carrying Two (2) marks. Attempt All questions.
1. The pinch off voltage Vp for a FET 3. A transistor in CE-configuration
is the drain to source voltage at has :
which : (A) high I/P and low O/P
resistance
(A) a considerable drain current
(B) low I/P and high O/P
starts flowing
resistance
(B) drain current does not flow
(C) low I/P and low O/P
(C) channel gets constricted resistance
(D) avalanche break-down occurs (D) high I/P and high O/P
resistance
2. A varactor diode is usually :
4. For an intrinsic semiconductor,
(A) Forward biased
Fermi level lies :
(B) Reverse biased
(A) at the mid gap
(C) Does not require bias (B) near the conduction band
(D) Both forward and reverse (C) near the valence band
biased (D) within conduction band
3 [P.T.O.
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5. Growth of single crystal Si is 7. If the base current of transistor is
noramlly favoured along :
100 mA and the current gain is 30,
(A) <1 1 1> direction
the emitter current is ................ .
(B) <0 0 1> direction
(A) 3.33 A
(C) <1 0 1> direction
(B) 3 A
(D) <1 1 0> direction
6. Match the pairs and select the (C) 3.1 A
correct answer from the codes given
(D) 30 A
below :
8. The maximum power that can be
List I
transferred to the load resistor
(a) Epitaxy
RL from the voltage source in the
(b) Electronic charge
figure shown below is :
(c) V-groove
(d) MOSFET
100 Ω
List II
+
(i) 1.6 × 10–19 coulombs
RL
(ii) Growth of single crystal Si 10 V –
(iii) Voltage controlled device
(iv) Isolation method
Codes :
(A) 1 W
(a) (b) (c) (d)
(A) (ii) (i) (iv) (iii) (B) 10 W
(B) (i) (iii) (ii) (iv)
(C) 0.25 W
(C) (iii) (iv) (i) (ii)
(D) 0.5 W
(D) (iv) (ii) (iii) (i)
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9. In the circuit shown in figure For answering Q. No. 10 and
Q. No. 11 refer to the circuit shown
the switch S has been opened for a
in the figure is initially under a
long time. It is closed at t = 0.
steady state condition :
The values of VL(0+) and IL(0+)
are ................................... .
1
2
The switch is moved from position 1
to position 2 at t = 0.
10. The current through inductor
immediately after switching
(A) 200 V, –5 A
is .......................... .
(B) 0 V, 5 A (A) 2 A
1
(B) A
2
(C) 100 V, 5 A
(C) 1 A
(D) 100 V, –5 A (D) 5 A
5 [P.T.O.
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11. The expression for current i(t) 13. The transmission parameters for
is .............................. .
the following circuit are :
(A) e –5t
(B) 2.e–5t
2 –5t
(C) .e
5 + 1Ω 2Ω +
(D) 5.e–2t
5Ω
12. For the network shown in the – –
following figure, the transfer
V2 ( s )
function V s is : 7 1 −119
1( ) (A) A = , B = , C = ,
5 5 50
D=
1 7 6
(B) A = , B = , C = ,
5 5 5
−119
D=
50
s2 − 1 −119
(A) (C) A = , B = , C = ,
2s 2 + 2 50
7
s2 − 1 D=
(B) 5
2s 2 − 1
s2 + 1 −119 7
(C) (D) A = , B = , C = ,
2s 2 + 1 50 5
s2 + 1 1
(D) D=
2s 2 − 1 5
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14. Match the following and select the • Choose the correct options in case
correct answer from the codes given of Q. No. 15 to Q. No. 18 after
below :
studying the following circuit :
List I
VCC
10 + 20 V
(a) s ( s + 10 )
R1
10 100 Ω
(b) 2 C1
s + 100 Q1
( s + 10 ) 10 µF
(c) 2 D1
( s + 10 ) + 100
(d) 10 D2
List II C2
(1) 10 δ(t)
10 µF 100 Ω
(2) [e–10t .cos10 t].u(t)
(3) [sin10 t] .u(t)
(4) [1 – e–10t].u(t) For Q 1 and Q 2 β ac = 50 and
ac emitter resistance re′ = 6 Ω.
Codes :
15. The maximum peak output
(a) (b) (c) (d)
voltage is :
(A) (3) (4) (1) (2)
(A) 5 V
(B) (3) (4) (2) (1) (B) 10 V
(C) (4) (3) (2) (1) (C) 15 V
(D) (4) (3) (1) (2) (D) 20 V
7 [P.T.O.
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16. The maximum peak output current 20. The following circuit stands for :
is :
(A) 1 A
(B) 0.75 A
(C) 2.25 A
(D) 1.25 A
17. The ac output power is :
(A) 12.5 W
(B) 6.25 W
(A) Buffer amplifier
(C) 7.96 W
(B) Inverting amplifier
(D) 25 W
18. The input resistance is : (C) Non-inverting amplifier
(A) 10 Ω
(D) Cascade amplifier
(B) 500 Ω
21. The volt-ampere equivalent of
(C) 700 Ω
temperature is :
(D) 1 kΩ
19. CMRR is the ratio of : kT
(A)
e
(A)
e
(B)
(B) Ad.Acm kT
Acm T
(C) (C)
Ad k.e.
1 .k
(D) (D)
Ad.Acm T.e.
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24. Which of the following describes the
22. Using four cascaded counters with basic operation of a single slope
A/D converter ?
a total of 16 bits, how many states
(A) The VCO quits changing
must be deleted to achieve a frequency when the input
voltage stabilizes. The
modulus of 50,000 ? frequency of the VCO, which is
proportional to the analog
(A) 50,000 voltage, is measured and is
displayed on the digital display
as a voltage reading
(B) 65,536
(B) A ramp generator is used to
enable a counter through a
(C) 25,536
comparator. When the ramp
voltage equals the input
(D) 15,536 voltage, the counter is latched
and then reset. The counter
23. If an analog signal is to be reading is proportional to
the input voltage since the
converted into digital with an ramp is changing at a constant
V/second rate
8 bit resolution, how many
(C) A ramp voltage and analog
input voltage are applied to a
comparators are used in a parallel
comparator. As the input
encoded ADC ? voltage causes the integrating
capacitor to charge, it will at
some point equals the ramp
(A) 127 voltage. The ramp voltage is
measured and displayed on the
(B) 128 digital panel meter
(D) The input is compared with the
(C) 255 number of levels of a resistive
ladder and the output is
(D) 256 encoded and displayed on a
digital panel meter
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25. Match List I with List II and select • Read the following and answer
the correct answer using the codes
the questions from 26 to 28 based
given below the lists :
on the same :
List I
A low power Schottky TTL is
(a) ECL
a modification of standard TTL
(b) CMOS
in which larger resistances
(c) TTL and Schottky diodes are used. The
(d) RTL larger resistances decrease the
List II power dissipation, and the Schottky
(i) Low power dissipation diodes increases the speed. In case
of such a low power Schottky TTL
(ii) Current mode logic
NOR gate, the specifications are as
(iii) Slow switching speed
follows :
(iv) Totem-pole arrangement
Parameter Value
Codes :
VCC 5 V
(a) (b) (c) (d)
I CH 1.6 mA (Feeding
(A) (iii) (iv) (i) (ii)
(B) (iv) (iii) (ii) (i) 4 gates)
(C) (ii) (i) (iv) (iii) ICL 2.8 mA (Feeding
(D) (i) (ii) (iii) (iv) 4 gates)
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VOH (min) 2.7 V 27. One of the following statements hold
good in case of the above referred
VOL (min) 0.4 V
low power Schottky TTL NOR gate.
VIH (max) 2.0 V Indicate the same :
VIL (max) 0.8 V (A) Both fan-out and fan-in are
same which is equal to 10
IOH (max) 4.0 mA (out)
(B) Fan-out and fan-in are different
IOL (max) 8.0 mA (in)
and their values are 10 and
IIH (max) 0.02 mA (in) 20 respectively
IIL (max) 0.4 mA (in) (C) Both fan-out and fan-in are
same which is equal to 20
tPLH 10 ns
(D) Fan-out and fan-in are different
tPHL 10 ns
and their values are 20 and 10
26. The power dissipation of the above respectively
referred low power Schottky TTL 28. The propagation delay of the
NOR gate is : above referred low power Schottky
TTL NOR gate is :
(A) 1.75 mW
(A) 10 ns
(B) 3.75 mW
(B) 20 ns
(C) 4.75 mW
(C) 30 ns
(D) 2.75 mW
(D) 40 ns
11 [P.T.O.
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29. Match List I (State diagram)
Read the following program written
with List II (name of the flip-flop)
and select the correct answers from in 8085 assembly language and
the codes given below the lists :
answer the question Nos. 30 to 32 :
List I
2000 LXI SP, # 2100 H
1/1
1/1 2003 LXI B, # 0000 H
(a) 0/0 0 1
0/0 2006 PUSH B
1/1 2007 POP PSW
0 1 1/1
(b) 0/0 2008 LXI H, # 200B H
0/0
200B CALL DELAY
10/1 00/1
00/0 200E OUT 01 H
(c) 0 1 10/1
01/0 01/0
2010 HLT
11/1
DELAY : 2064 PUSH H
10/1 00/1
00/0
0 1 10/1 2065 PUSH B
(d) 01/0 01/0
11/1 2066 LXI B, # 80FF H
List II
(i) S-R- flip-flop LOOP : 2069 DCXB
(ii) D-flip-flop
206A MOV A, B
(iii) J-K flip-flop
(iv) T-flip-flop 206B ORA C
Codes :
(a) (b) (c) (d) 206C JNZ LOOP
(A) (i) (ii) (iii) (iv)
(B) (i) (iii) (iv) (ii) 206F POP B
(C) (ii) (iv) (i) (iii)
(D) (iii) (i) (ii) (iv) 2070 RET
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30. The memory location where the 33. Arrange the following in descending
order the type of memory depending
program return after the subroutine
on speed of operations :
is ............................. .
(a) static RAM
(A) (200B)H (b) static ROM
(B) (2064)H (c) dynamic RAM
(C) (2069)H (d) flash RAM
(A) (a) (b) (c) (d)
(D) (2070)H
(B) (a) (c) (d) (a)
31. The status of the flags and the (C) (d) (a) (c) (b)
contents of the accumulator after the
(D) (d) (c) (a) (b)
execution of the POP instruction
34. In interfacing the memory
located at (2007)H is .............. . externally to an 8085 microprocessor
the following signals are required :
(A) Sign flag set, (ACC) = (00)H
(A) Address and data bus
(B) Sign flag reset, (ACC) = (FF)H
(B) Control bus RD, WR, chip select
(C) All flag reset, (ACC) = (00)H signal OE ( )
(C) Only address Bus and RD, WR,
(D) All flag set, (ACC) = (FF)H
OE signal
32. The contents of the stack pointer (D) Both (A) and (B)
register and the program counter 35. I/O in 8085 based system can be
after the execution of CALL accessed by :
instruction are as follows : (A) I/O instructions
(B) Memory instructions
(A) SP = (2069)H PC = (200E)H
(C) I/O and memory instructions
(B) SP = (20FE)H PC = (2064)H
(D) I/O or memory instructions
(C) SP = (2010)H PC = (2000)H depending on which I/O is
connected as I/O map or
(D) SP = (200B)H PC = (200B)H memory map
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36. Match the following peripherals of 38. The C programming language
8085 band system with the function provides some of the following basic
they can perform and select the data types. Match with suitable
correct answer from the codes given examples and select the correct
below : answer from the codes given below :
I/O device/chip Type
(1) 8155 (1) long int
(2) 8255 (2) long double
(3) 8279 (3) unsigned long int
(4) 8253 (4) _Bool
Function Constant examples
(a) I/O + RAM (i) 0, 1
(b) Keyboard and Display (ii) 12.34, 3.1 e–5
(c) Timer and Counter (iii) 12.341, 3.1 e–51
(d) I/O port only (iv) 12411, oxffee UL
(v) 12 L, –97, OXFFEO
(e) Serial Rs 232
Codes :
Codes :
(1) (2) (3) (4)
(1) (2) (3) (4)
(A) (v) (iii) (i) (v)
(A) (a) (d) (b) (c)
(B) (ii) (iv) (ii) (v)
(B) (d) (a) (c) (b)
(C) (iii) (ii) (i) (iv)
(C) (c) (d) (a) (b)
(D) (v) (iii) (iv) (i)
(D) (b) (c) (e) (d)
39. Translation of assembly code into
37. In C programming a comment can
machine code in an embedded
be initiated by the : system is performed by :
(A) / and * (A) Assembler
(B) / & // (B) Compiler
(C) * and ** (C) Linker
(D) * & / (D) Locator
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40. A list in which each entry contains
42. The data transmitted by a device
a pointer to the preceding entry in
the list as well as pointer to the next connected to serial port is properly
entry in the list is known as :
displayed on a hyperterminal if :
(A) Tree
(B) Double linked list (A) the bit length is 8 bits only
(C) Circular list
(B) the baud rate of transmission
(D) Singly linked list
and reception are matched
41. Assertion (A) : The programmer
doesn’t have to
(C) the correct decryption algorithm
write the printf
and scanf routines is used
because.
(D) proper graphics adapter is used
Reason (R) : Both printf and
scanf are part of
43. Given a uniform ring of charge
the standard C
library. with opposite charge located at the
(A) Both (A) and (R) are true and
center, the net force on the central
(R) is the correct explanation
of (A) charge is :
(B) Both (A) and (R) are true but
(A) Outward
(R) is not the correct
explanation of (A)
(B) Inward
(C) The (A) is true but (R) is
false (C) Zero
(D) The (A) is false but (R) is
true (D) Out of plane
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λ
44. A transformer in a transmission
4
line helps in :
(A) reducing voltage
(B) increasing voltage
(C) reflecting the voltage
(D) matching the impedance
45. The reflection coefficient for a Figure shows construction of a
system is |ρ|ejθv. For a particular hybrid ring with four ports for
load arrangement, first minimum
question nos. 46 and 47.
from the load is at . The angle
46. For an input at port P1, the output
θv is :
appears at :
(A)
(A) P2
(B) – (B) P2, P3
(C) 0 (C) P3, P4
(D) π (D) P2, P4
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47. For an input at port P2, the output 51. The maximum frequency deviation
appears at : is .............................. .
(A) P3, P4 (A) 3 kHz
(B) 2 kHz
(B) P1, P4
(C) 4 kHz
(C) P4 only
(D) 1 kHz
(D) P1, P3
52. The random variable X has the
48. In a metallic cylindrical wave probability function :
guide the boundary conditions fx(x) = k, for x = 0
require that component : = 2k, for x = 1
(A) Eφ = 0 = 3k, for x = 2
(B) Er = 0 = 0, otherwise
(C) Ez = 0 Then k is .............................. .
(D) Eφ = Ez = 0 1
(A)
49. For a plane polarized wave moving 2
in z-direction with Ex and Hy as its 1
(B)
components, ratio Ex/Hy is : 6
(A) 3 × 108 Ω 1
(C)
(B) 75 Ω 3
(C) 377 Ω 5
(D)
(D) 50 Ω 6
The modulation is given by 53. An RC filter based pre-emphasis
V(t) = 100 cos[2πfct + 4sin 2000πt] de-emphasis is employed in FM
and fc = 10 MHz. system. The de-emphasis first
order RC filter has R = 2 kΩ,
Answer question Nos. 50 and 51
C = 0.05 µF. The gain in dB for
based on this information.
the FM broadcasting system
50. The average transmitted power which has the base bandwidth of
is ............................... . 15 kHz is :
(A) 5 kW (A) 5.4 dB
(B) 3 kW (B) 1.5 dB
(C) 2 kW (C) 18.8 dB
(D) 4 kW (D) 7.3 dB
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54. Match the following lists. List I is 55. Six message signals each of
name of a shift keying technique bandwidth 5 kHz are time division
and List II represents wave forms.
multiplexed and transmitted. The
Choose the correct answer from the
signaling rate the minimum channel
codes given below :
bandwidth for the PAM/TDM
List I
channel will be :
(a) BFSK
(A) 60 K bits/s and 30 kHz
(b) ASK
(B) 30 K bits/s and 60 kHz
(c) BPSK
(d) QPSK (C) 10 K bits/s and 30 kHz
(D) 480 K bits/s and 240 kHz
List II
56. Assertion (A) : PCM is a “digital”
(i) modulation system
because.
(ii) Reason (R) : The PCM system
consists of an
(iii) encoder and a
decoder.
(iv)
(A) Both (A) and (R) are true and
Codes : (R) is the correct explanation
of (A)
(a) (b) (c) (d)
(B) Both (A) and (R) are true and
(A) (ii) (i) (iv) (iii)
(R) is not the correct
(B) (iv) (iii) (i) (ii) explanation of (A)
(C) (ii) (iii) (iv) (i) (C) The (A) is true but (R) is false
(D) (iv) (iii) (ii) (i) (D) Both (A) and (R) are false
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57. A communication system consisting 60. Match the items from List I with
List II and select the correct answer
of six messages with probabilities
from the codes given below :
1 1 1 1 1 1 List I
, , , , and respectively,
4 4 8 8 8 8 (a) SCR
the entropy of the system would (b) UJT
(c) IGBT
be :
(d) Diode
(A) 16 bits/message List II
(i) Rectifier
(B) 2.5 bits/message
(ii) Half-wave controlled rectifier
(C) 3 bits/message (iii) Trigger device
(iv) Low voltage drop power device
(D) 12 bits/message
Codes :
58. The IGBT has the following draw- (a) (b) (c) (d)
back : (A) (iii) (iv) (i) (ii)
(B) (ii) (iii) (iv) (i)
(A) Low voltage and current rating (C) (i) (ii) (iii) (iv)
(B) High switching losses (D) (iv) (iii) (ii) (i)
61. Assertion (A) : IR lasers are
(C) Long turn on and turn off times used for long haul
transmission
(D) High conduction losses
with operating
59. A three phase half wave rectifier frequency 193
THz.
has a supply of 150 V/phase. What
Reason (R) : The line width of
is the required diode PRV rating ? semiconductor
Assuming the load current is level lasers are of the
order of fraction
at 25 A, and each diode has a volt- of nm.
drop of 0.7 V. (A) Both (A) and (R) are true and
(R) is the correct explanation
(A) 152 V of (A)
(B) 286 V (B) Both (A) and (R) are true but
(R) is not the correct
(C) 386 V explanation of (A)
(C) (A) is true and (R) is false
(D) 552 V
(D) (A) is false but (R) is true
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62. Match the items from List I with 64. Silicon P-i-N detector are not
List II and select the correct answer suitable for the following
from the codes given below : wavelength :
List I (A) 850 nm
(a) Silicon (B) 1060 nm
(b) GaAs (C) 630 nm
(c) Silica (D) 1300 nm
(d) Water 65. The following are the losses found
List II in fiber joints :
(i) Impurity (a) Lateral misalignment
(ii) Detection (b) Angular misalignment
(iii) Photo-emission (c) Longitudinal misalignment
(iv) Optical fiber (d) Reflection loss
Codes : Arrange these losses in increasing
(a) (b) (c) (d) order :
(A) (ii) (iii) (iv) (i) (A) (a) (b) (c) (d)
(B) (iv) (iii) (i) (ii) (B) (c) (b) (a) (d)
(C) (ii) (iv) (iii) (i) (C) (d) (c) (b) (a)
(D) (c) (a) (d) (b)
(D) (iii) (i) (ii) (iv)
66. Match the following and select the
63. Match the items from List I with
correct answer from the codes given
List II and select the correct answer
below :
from the codes given below :
List I
List I
(i) Resistive
(a) PN Diode
(ii) Capacitive
(b) PIN Diode
(iii) Photovoltaic
(c) Avalanche Diode
(iv) Electromagnetic
(d) LDR
List II
List II (a) Limit switches
(i) Broadband (b) Temperature, pressure
(ii) High quantum efficiency (c) Velocity acceleration
(iii) Low cost (d) Sound pressure, moisture
(iv) High speed (e) pH and condutivity
Codes : Codes :
(a) (b) (c) (d) (i) (ii) (iii) (iv)
(A) (ii) (i) (iv) (iii) (A) (c) (a) (e) (b)
(B) (iii) (ii) (iv) (i) (B) (b) (d) (a) (c)
(C) (iv) (iii) (i) (ii) (C) (a) (c) (b) (d)
(D) (i) (iv) (iii) (ii) (D) (d) (a) (b) (c)
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67. The factors that affect the 69. The following precautions should be
observed when using ammeter for
measurement are : measurement :
(i) Never connect an ammeter
(A) The measuring instrument and
across a source of emf
environmental conditions (ii) Using multirange meter use
lowest current first
(B) The measuring instrument (iii) Using multirange meter use
and the person using the highest range first
(iv) Observe the correct polarity
instrument
if analog type ammeter is
(C) The person using instrument used
(A) (i) only
and environmental condition (B) (i) and (iii)
(C) (i), (iii) and (iv)
(D) The measuring instrument, the
(D) (ii) only
person using instrument and 70. A certain crystal has a coupling
enviromental conditions coefficient of 0.32. How much
electrical energy must be applied to
68. Measuring in process control is produce an output of 1 oz. in of
mechanical energy.
basically used to monitor the :
(1 oz. in = 7.06 × 10–3 J)
(A) Process input parameters (A) 22.19 mJ
(B) 2.219 mJ
(B) Process input and output (C) 221.9 mJ
parameters (D) 0.2219 mJ
71. The post-deflection acceleration in a
(C) Process input, output and CRT is used in high frequency
oscilloscopes mainly to :
sorrounding environmental
(A) increase the deflection
parameters sensitivity
(B) improve the beam focussing
(D) Process output and
(C) improve the deflection linearity
environmental parameters (D) improve the spot brightness
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72. A 10-bit successive approximation 75. The approximate Bode magnitude
type A/D converter working in the
range of 0-10 V takes 50 µs to plot of a minimum phase system
analog signal of 10 volts. Then the is shown in the following figure.
time it takes to convert 5 V signal
The transfer function of the system
would be :
(A) 25 µs is ................................... .
(B) Slightly more than 25 µs
dB
(C) Slightly less than 25 µs
160
(D) 50 µs
140
73. Temperature was measured in eight
locations in a room and the values
obtained were 21.2°, 25.0°, 18.5°,
22.1°, 19.7°, 27.1°, 19.0° and 20.0°C 20
then the arithmetic mean and
standard deviation will be :
w
ω
(A) 21.6°C and 3.04°C 0.1 10 100100
(B) 21.7°C and 3.03°C
3
(C) 21.8°C and 3.02°C 8 ( s + 0.1 )
(A) 10 . 2
(D) 21.5°C and 3.04°C ( s + 10 ) ( s + 100 )
74. If the Nyquist plot cuts the negative 3
real axis at a distance of ................, 7 ( s + 0.1)
(B) 10 .
then the gain margin of the system ( s + 10) ( s + 100 )
is –2.5 dB. 2
8 ( s + 0.1)
(A) 0.2 (C) 10 . 2
( s + 10 ) ( s + 100 )
(B) 0.4
3
(C) 0.6 9 ( s + 0.1)
(D) 10 . 2
(D) 1.333 ( s + 10 ) ( s + 100 )
22
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ROUGH WORK
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DEC - 38313/III
ROUGH WORK
24Official key not published for this paper.
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Source: Savitribai Phule Pune University. Question paper published by Savitribai Phule Pune University.