MSE15

Time:03 Hours Booklet No: ________________

Max. Marks: 150

Roll No:_________________ Name of the Candidate: _________________________________________________________________ (in capital letters)

Name of the Centre : __________________________________________________________________

Signature of the Candidate

Instructions 1. Fill up the information above with a Pen/Ball Point Pen (Black or Blue). 2. The answer sheet is placed inside the test booklet. Without breaking the seal of the Test Booklet, take the

Answer Sheet out. Don’t break open the seal until you are asked to do so. 3. There are 150 questions. Each correct answer gets a score of one mark. There is no negative marking. 4. Each question is followed by four answers. You should select one answer from A, B, C or D considered by

you as the most appropriate or correct answer and color the appropriate circle using a black or blue ball pen.

5. Do your rough work only on the blank pages provided at the end of the question booklet. 6. Mobile phone, calculators, calculator-watch, slide rules, mathematical table, etc. are not allowed in the

examination hall. 7. Make sure that you do not possess any pages (Blank or Printed) or any unauthorized material. If such

material is found in your possession during the examination, you will be disqualified from entrance examination.

8. If you are found copying/helping others you will be disqualified from the entrance examination. 9. Do not leave examination hall until you have recorded your attendance and submitted the Answer Sheet

to the Invigilator. 10. You are not allowed to leave the examination hall till the end of the examination. 11. Ensure that there are 48 pages in this Test Booklet (including front and back page). 12. At the end of examination, candidate is permitted to take the question booklet.

P.T.O

2

3

Useful constants

Electron mass (m0) : 9.10 × 10-31

kg

Electron charge (q) : 1.60 × 10-19

C

Planck‘s constant (h) : 6.62 × 10-34

m2kg/s

Boltzmann constant (kB) : 1.38 × 10-23

J/K

Permittivity of free space (𝜀0) : 8.85 × 10-12

F/m

Permeability of free space (𝜇0) : 4π × 10-7

H/m

4

5

001. A unit vector orthogonal to both and

A.

√

B.

√

C.

√

D.

√

002.

( )

is identical to --------------------------- for -1 < x < 1

A.

B.

C.

D.

003. If the given matrix

(

)

is orthogonal, then can have which of the following value

A. √

B. 0

C. 1

D.

√

6

004. If one of the eigen values of matrix [

] is 2, then what is the normalized eigen

vector corresponding to this eigen value?

A.

2

1,

2

1,0

B.

2

1,

2

1,0

C.

2

1,

2

1,0

D. 0 1, 0,

005. Match the application to the appropriate numerical method.

P1: Numerical integration M1: Newton-Raphson Method

P2: Solution to a transcendental equation M2: Runge-Kutta Method

P3: Solution to a system of linear

equations

M3: Simpson‘s 1/3-rule

P4: Solution to a differential equation M4: Gauss Elimination Method

A. P1—M3, P2—M2, P3—M4, P4—M1

B. P1—M4, P2—M1, P3—M3, P4—M2

C. P1—M2, P2—M1, P3—M3, P4—M4

D. P1—M3, P2—M1, P3—M4, P4—M2

006. In the limit 0x the function )sin(

)sin()(

x

Gxxf takes the value

A. zero

B. one

C. G

D. Infinity

007. The average value of the function ( ) in the interval 1 to 3 is

A. 40

B. 15

C. 80

D. 20

7

008. The solutions of the differential equation given below are

0)(d

d

d

d 22

2

22 ynx

x

yx

x

yx

A. Legendre Polynomials

B. Bessel Functions

C. Hermite Polynomials

D. Laguerre Polynomials

009. The Newton Raphson Method is used to solve the equation 0855)( 23 xxxxf .

Taking the initial guess as 5x , the solution at the end of the first iteration is

A. 5.566

B. 6.764

C. 4.434

D. 3.236

010. A phasor (complex number) is given by 1201a . The value of

2a is

A. j0.866-1

B. j0.866-0.5

C. j0.866-0.5-

D. j0.8660.5-

011. Evaluate ii 31

1

31

1

A. -5

3

B. 4

3

C. 5

3

D. -4

3

8

012. The value of dz iz

z

z

2

63

is

A. i

68

B. i316

1

C. i

68

D. i316

1

013. Laplace transform of ( )

is

A.

( )

B.

( )

C.

( )

D.

( )

014. A unit normal to the surface 10542 22 zyzx at the point P (3, -1, 2) is

A. 7

623 kji

B. 7

623 kji

C. 49

623 kji

D. 49

623 kji

015. The inverse Laplace Transform of 96

6)(

2

sssF is

A. tt 3e6

B. t3e6

C. t3e8

D. tt 3e9

9

016. The Fourier Transform of a function ta

tf

e)( is given by

A. 22

2

a

B. 22

2

a

a

C. 22

2

a

j

D. ja

1

017. A uniform plane wave in air is incident on an infinitely thick glass slab, refractive index

1.5. The percentage of power reflected from the glass air interface is

A. 0

B. 20

C. 10

D. 4

018. Consider light passing through a polarizer analyzer pair, in which the analyzer pass axis is

at an angle of 45 degrees to that of the polarizer. An optical component introduced

between the polarizer and analyzer can make the output intensity zero. The component

can be a

A. quarter-wave plate

B. plane glass sheet

C. full-wave Plate

D. half-wave plate

019. According to Debye theory, the specific heat of a solid is proportional to

A. 3T

B. 0T

C. 2T

D. 5T

10

020. The fundamental frequency (ω) of string of length L, tension T and mass per unit length µ

is given by

A.

T

L

B.

T

C. L

T

D.

TL

021. ‗Zero point energy‘ is a result of

A. Relativity effects

B. Pauli‘s exclusion principle

C. Uncertainty principle

D. Energy conservation

022. The torque on a particle at position

r with momentum

p is given by

A. dt

pdp

B. dt

rdr

C. dt

pdr

D.

dt

pdr

dt

d

11

023. The de-Broglie wavelength of particles with mass m and average momentum at a

temperature T in three dimension is given by

A. Tmk

h

B2

B. Tmk

h

B3

C. m

h

2

D. Tk

h

B2

024. In C language, what is the output of the following code

main()

{

int i=-3,j=2,k=0,m;

m=++i||++j&&++k;

printf("\n%d%d%d%d",i,j,k,m);

}

A. -2 2 1 0

B. -2 2 0 1

C. -2 3 1 1

D. -2 3 0 0

025. Using hierarchy of operations in C language, what would be the value of integer i in the

following expression?

i = 2 * 3 / 4 + 4 / 4 + 8 - 2 + 5 / 8

A. 7

B. 1

C. 0

D. 8

12

026. In C language, what is the output of the following code?

main()

{

int arr[]={12,13,14,15,16};

printf("\n%d%d%d", sizeof(arr),sizeof(*arr),sizeof(arr[0]));

}

A. 10 2 2

B. 5 2 2

C. 4 1 1

D. 5 1 1

027. In C language, what is the output of the following code?

int main()

{

int ***r, **q, *p, i=8;

p = &i;

q = &p;

r = &q;

printf("\n%d%d%d", *p, **q, ***r);

}

A. 7 7 7

B. 6 6 6

C. p q r

D. 8 8 8

13

028. In the C program mentioned below, how many times does "abcd" get printed?

int main()

{

int x;

for(x=-1; x<=10; x++)

{

if(x < 5)

continue;

else

break;

printf("abcd");

}

return 0;

}

A. 11 times

B. 10 times

C. 0 times

D. infinite times

029. Which of the following is an example of line defect in crystals?

A. vacancies

B. staking faults

C. interstitials

D. dislocations

030. The second energy state of a particle of mass ‗m‘ in a one-dimensional box of length ‗L‘ is

A. 2

2

8mL

h

B. 22mL

h

C. 2

2

2mL

h

D. mL

h

2

14

031. In a crystalline solid, the energy band structure (E-k relation) for an electron of mass m is

given by 0

2

2

8

)85(

m

kkhE

The effective mass of an electron in the crystal is

A. 08m

B. 02m

C. 5

2 0m

D. 5

0m

032. Consider a doped semiconductor having electron and hole mobilities µn and µp

respectively. Its intrinsic carrier density is ni. The electron concentration n for which the

conductivity is minimum at a given temperature is

A. (

)

B. (

)

C. (√

)

D. (√

)

033. An n-type silicon bar is 0.1 cm long and 100 μm2 in cross-sectional area has a majority

carrier cocentration of 5×1020

/m3 and the carrier mobility is 0.13 m

2/V-s at 300 K. If the

charge of an electron is 1.6×10-19

C, then the resistance of the bar is

A. 104 Ω

B. 10-1

Ω

C. 106 Ω

D. 10-4

Ω

15

034. Mobilities of electrons and holes in a sample of intrinsic germanium at room temperature

are 0.36 m2/V-s and 0.17 m

2/V-s respectively. If the electron and hole densities are each

equal to 2.5x1019

m-3

, the resistivity of germanium is

A. 0.70 Ω.m

B. 1.47 Ω.m

C. 2.12 Ω.m

D. 0.47 Ω.m

035. A diode that has a negative resistance characteristic is the

A. Tunnel diode

B. Zener diode

C. Varactor diode

D. LED

036. If mobility of an electron in Si at 300 K is 1200 cm2/V.s, then the diffusion coefficient of

the electron is

A. 31.01 m2/s

B. 15.50 m2/s

C. 31.01 cm2/s

D. 15.50 cm2/s

037. Solar energy travels through space by the process of

A. convection

B. radiation

C. conduction

D. transportation

038. An n-type bar of silicon having cross sectional area 1.0 mm2 has an effective carrier

density 1016

/cm3. What is the drift velocity of electrons if 50 mA current is flowing

through the bar?

A. 3.125 × 103 cm/s

B. 3.125 × 105 cm/s

C. 3.125 × 109 cm/s

D. 3.125 × 107 cm/s

16

039. The effective mass of an electron in GaAs is 0

* 0852.0 mm . What is the thermal velocity

of electrons in GaAs at room temperature?

A. 7.26 × 105 m/s

B. 4.00 × 105 m/s

C. 5.65 × 105 m/s

D. 8.70 × 105 m/s

040. Schottky defect is

A. a line defect in ionic crystal

B. a point defect in metals

C. a point defect in ionic crystals

D. a line defect in metal

041. Built-in potential of silicon p-n junction with doping densities Na and Nd at 300 K

A.

(

)

B.

(

)

C. (

)

D.

(

)

042. Pinch-off voltage in JFET is

A. the gate to source voltage that gives unity drain current

B. a drain voltage that gives zero drain current

C. the gate to source voltage that gives zero drain current

D. the drain voltage that gives infinite drain current

17

043. In a ruby laser, laser action is due to

A. oxygen atoms

B. Al2O3 crystal

C. aluminum atoms

D. chromium atoms

044. A voltage of 2.5 V is applied along the length 100 nm long with cross-sectional area

0.01 µm2. If the material is doped with Nd = 10

18 /cm

3, what is the current density?

( mobility of electron is )

A. 9.25 104 mA/cm

2

B. 9.25 106 mA/cm

2

C. 9.25 106 A/cm

2

D. 9.25 104 A/cm

2

045.

Consider an abrupt pn junction. Let Vbi be the built-in potential of this junction and VR be

the applied reverse bias. If the junction capacitance Cj is 1 pF for Vbi+VR = 1V, then for

Vbi+VR = 4V, Cj will be

A. 0.5 pF

B. 4.0 pF

C. 2.0 pF

D. 0.25 pF

046. Consider a p-n junction, the doping concentrations on the p side and n side are

NA = 9 × 1016

/cm3 and ND = 1 × 10

16 /cm

3 respectively. The p-n junction is reverse biased

and the total depletion width is 3 μm. The depletion width on the p side is

A. 0.3 μm

B. 2.7 μm

C. 0.75 μm

D. 2.25 μm

18

047. Early effect in a bipolar transistor refers to a reduction of the effective base width caused

by

A. electron hole recombination at the base

B. the reverse biasing of the base collector junction

C. the forward biasing of emitter base junction

D. the early removal of stored base charge during saturation to cut-off switching

048. The concentration of minority carriers in an extrinsic semiconductor under equilibrium is

A. inversely proportional to the doping concentration

B. directly proportional to the doping concentration

C. inversely proportional to the intrinsic concentration

D. directly proportional to the intrinsic concentration

049. An electron beam consisting of electrons with velocity 0 passes through a space

with magnetic field of weber/m2 and electric field

V/m. If the force due to the two fields is equal and opposite the value of 0 is

A. 3.4 104

m/s

B. 6.8 104

m/s

C. 1.7 107 m/s

D. 4.25 105

m/s

050. An ammeter of resistance 1.5 can measure currents up to 5 A. In order to measure a

maximum current of 30 A, the value of a the shunt resistance to be added is

A. 0.25

B. 0.15

C. 0.3

D. 0.1

19

1 Ω

A

S

B

+

V0

-

10 V

1 Ω

2 Ω

I +

051. The full scale deflection of a millivoltmeter which has a resistance of 40 is 800 mV. To

convert this millivoltmeter into a milliammeter, a shunt resistance of 10 is connected.

The new full scale deflection is for a current of

A. 0.01 A

B. 100 mA

C. 10 mA

D. 1 A

052. The resistance of a nickel coil at 20 C is 25 and it rises to 37.5 when the coil is

immersed in a liquid. If the temperature coefficient of nickel at 20 C is = 0.00625 /K,

what is the temperature of the liquid?

A. 80 C

B. 100 C

C. 120 C

D. 40 C

053. In a circuit consisting of R, L, and C in series, the Q-factor is

A. LC

R

B. L

C

R

1

C. C

LR

D. C

L

R

1

054. The voltage (V0) across the 2 Ω resistor shown in figure is

A. 2.5 V

B. 5 V

C. 10 V

D. 7.5 V

20

055. In the circuit shown in the figure, what should be the value of RL for maximum power

transfer?

A. 50 Ω

B. 65 Ω

C. 73 Ω

D. 13 Ω

056. A series RLC circuit has a resonance frequency of 12000 Hz. If R = 5 Ω and if XL at

resonance is 300 Ω then the bandwidth is

A. 2 kHz

B. 400 Hz

C. 4 kHz

D. 200 Hz

057. If each branch of a Delta circuit has impedance Z5 , then each branch of the equivalent Y

circuit has impedance

A. Z5

B. Z55

C. 5

Z

D. 5

Z

21

058. A series RC circuit is connected to a DC voltage source at time t=0. Which of the

following represents the current i(t) ?

059. The Q-factor of a parallel resonance circuit consisting of an inductance of value 1 mH,

capacitance of value and a resistance of 100 Ω is

A. 100

B.

C. 10

D. 1

060. The voltage across an inductor is given by ( ) V at Find the current across

inductor, assume inductance of inductor to be

A. ( )

B. ( )

C. ( )

D. ( )

22

061. A d.c. constant voltage source feeds a resistance of in series with capacitor.

Find the time taken for the capacitor when charge retained will be decayed to 50% of the

initial value.

A. ( )

B. ( )

C. ( )

D. ( )

062. The ‗Z‘ parameters of the network shown is

A. *

+

B. *

+

C. *

+

D. *

+

063 Voltage across the 5 A source in the given circuit is?

A. 12.5 V

B. 20 V

C. 25 V

D. 17.5 V

064. A lamp rated 10 W, 50 V is proposed to be used in a 110 V system, the wattage and

resistance of the resistor to be connected in series with the lamp is

A. 12 W, 300 Ω

B. 10 W, 250 Ω

C. 15 W, 300 Ω

D. 10 W, 300 Ω

23

065. The current I, in the figure shown below is

A. 3 A

B. 6 A

C. 1 A

D. 2 A

066. KCL is a consequence of the law of conservation of

A. energy

B. flux

C. charge

D. all of the above

067. The resistance between opposite faces of a 1 m cube is 1 Ω. If the length is increased to

2 m with the volume remaining the same, then the resistance between the opposite faces

along its length is

A. 4 Ω

B. 1 Ω

C. 2 Ω

D. ½ Ω

068. A source voltage of 10 V is applied to a series resonant circuit LCR, where R = 5 and

L = 2 mH. If the resonant frequency is 5 kHz, the voltage across L or C at resonance is

A. 154 V

B. 197.3 V

C. 105.9 V

D. 125.6 V

24

069. A transistor with a forward current gain hf of 150, is connected to a load. The load consists

of a tank circuit with L= 400 µH and 10 , and C = 200 pF. If the input resistance is

3 k, the voltage gain will be

A. 5,500

B. 2,750

C. 6,500

D. 10,000

070. For op-amp having a slew rate of SR = 2 V/µs, the maximum closed loop voltage gain

that can be used when the input signal varies by 0.5 V in 10 µs is

A. 4

B. 20

C. 40

D. 2

071. An amplifier has an operating bandwidth given by ‗BW‘. If ‗n‘ stages of such amplifier

are cascaded, the bandwidth will become

A.

12

1

n

BW

B. BWn.

C. 12. nBW

D. 12 n

BW

072. The second harmonic distortion in an amplifier is reduced from 5% to 1% due to negative

feedback. The amplifier gain is 1000, the feedback ratio will be

A. 0.008

B. 0.02

C. 0.01

D. 0.004

25

073. A Zener regulator has an input voltage that varies from 15 to 20 V and a load current that

varies from 5 to 20 mA. If the Zener voltage is 6.8 V, the maximum value of series

resistor is

A. 410

B. 660

C. 320

D. 570

074. An amplifier comprises of four stages in CE configuration and the overall gain is 9 104.

If the first two stages have a voltage gain of 20 per stage and other two stages are

identical, the gain per stage of other two stages is

A. 22

B. 30

C. 18

D. 15

075. In the given figure what is the base current if ?

A.

B.

C.

D.

076. A forward voltage of 9 V is applied to a diode in series with a 1 kΩ load resistor. The

voltage across load resistor is zero. It indicates that

A. diode is open circuited

B. diode is short circuited

C. resistor is open circuited

D. diode is either short circuited or open circuited

26

077. If an op-amp has open loop voltage gain and internal output impedance

(without feedback) , then the closed loop voltage gain and output impedance

respectively are

A.

B.

C.

D.

078. The closed-loop voltage gain of the amplifier when and is

A. 20

B. 0

C. 21

D. 150

079. In a Op-Amp, a very high value of CMRR(common-mode rejection ratio) means that the

A. open-loop differential voltage gain is low and the common-mode gain is high.

B. open-loop differential voltage gain is high and the common-mode gain is high.

C. open-loop differential voltage gain is high and the common-mode gain is low.

D. open-loop differential voltage gain is low and the common-mode gain is low.

27

080. For the voltage divide circuit used to bias a silicon transistor shown in figure, the values of

emitter voltage and collector emitter voltage are (Given IC = IE )

A. 4.1 V, 9.0 V

B. 4.1 V, 13.0 V

C. 12.5 V, 9.0 V

D. 12.5 V, 13.0 V

081. In a Wein-bridge oscillator, positive feedback circuit is

A. an LC circuit

B. a voltage divider

C. a lead-lag circuit

D. an RL circuit

082. For a JFET, with parameters mA0.3DSSI , V6offGSV (max) and μS 5000max0 mg at

VGS = -4V the forward transconductance and ID are

A. 667 µS, 233 µA

B. 5000 µS, 233 µA

C. 500 µS, 233 µA

D. 1667 µS, 333 µA

083. If (734)8 = (x)16 , the value of x is

A. D C 1

B. C 1 D

C. 1 D C

D. 1 C D

28

084. In the circuit shown diodes D1, D2 and D3 are ideal and the inputs E1, E2 and E3 are 0 V for

logic 0 and 10V for logic 1. What logic gate does the circuit represent?

A. 3 input OR gate

B. 3 input AND gate

C. 3 input NOR gate

D. 3 input XOR gate

085. Which of the following is the fastest logic family?

A. TTL

B. ECL

C. CMOS

D. LSI

086. How many Select lines will a 32: 1 multiplexer have?

A. 8

B. 9

C. 4

D. 5

087. The logic circuit given below converts a binary code y1y2 y3 into:

A. BCD

B. gray code

C. excess-3

D. hamming

29

088. Simplify the Boolean expression F = C(B + C)(A + B + C).

A. C

B. A

C. B

D. ABC

089. A 4-bit synchronous counter uses flip-flops with propagation delay times of 15 ns each.

The maximum possible time required for change of state will be

A. 30 ns

B. 45 ns

C. 60 ns

D. 15 ns

090. The binary equivalent of decimal 5.375 is

A. 101.10111011

B. 101011

C. 101.011

D. 010111

091. Convert the following SOP expression to an equivalent POS expression.

A. ( )( )( )

B. ( )( )( )

C. ( )( )( )

D. ( )( )( )

30

092. How many gates would be required to implement the following Boolean expression

before simplification?

( ) ( )

A.

B.

C.

D.

093. Half Adder can be implemented by using ‗k‘ NAND gates. The value of ‗k‘ is

A.

B.

C.

D.

094. The output of a logic gate is 1 when all its inputs are at logic 0. The gate is either

A. OR or EX-NOR

B. NAND or EX-OR

C. AND or EX-OR

D. NOR or EX-NOR

095. The output Y of the circuit below is ‗1‘ when

A. two of more of the inputs P, Q, R are ―1‖.

B. two of more of the inputs P, Q, R are ―0‖.

C. any odd number of the inputs P, Q, R is ―0‖.

D. any odd number of the inputs P, Q, R is ―1‖.

31

096. What is the largest value of output voltage from an eight- bit DAC that produces 1.0 V for

a digital input of 00110010?

A.

B.

C.

D.

097. Simplify the Boolean function

A.

B.

C.

D.

098. Interfacing devices for DMA controller , programmable interval timer are respectively

A. 8253, 8259

B. 8257, 8253

C. 8257, 8251

D. 8251, 8259

099. The speed of a microprocessor depends on

A. clock

B. data bus width

C. size of register

D. address bus width

100. The status that cannot be operated by direct instruction is

A. AC

B. CY

C. Z

D. P

32

101. In an 8086 microprocessor, which one of the following instructions is executed before an

arithmetic operation?

A. AAM

B. DAS

C. DAA

D. AAD

102. In a microprocessor, the service routine for a certain interrupt starts from a fixed location

of memory which cannot be externally set, but the interrupt can be delayed or rejected.

Such an interrupt is

A. non maskable and vectored

B. maskable and non-vectored

C. non maskable and non-vectored

D. maskable and vectored

103. In a 16-bit microprocessor, words are stored in two consecutive memory locations. The

entire word can be read in one operation provided the first

A. word is even

B. memory address is even

C. word is odd

D. memory location is odd

104. The ESC instruction of 8086 may have two formats. In one of the formats no memory

operand is used. Under this format, the number of external op-codes (for the co-processor)

which can be specified are

A. 256

B. 512

C. 128

D. 1024

33

105. The first microprocessor to include Virtual memory in the Intel microprocessor family

was

A. 80286

B. 80386

C. 80486

D. Pentium

106. Which of the following instructions of an 8086 microprocessor uses the content of a CX

register as a counter?

1. LOCK

2. LOOP

3. ROTATE

A. Only 1 and 3

B. Only 1 and 2

C. 1,2 and 3

D. Only 2 and 3

107. In 8085 , if the clock frequency is 5 MHz, the time required to execute an instruction of 18

T-states is

A. 3.0 µs

B. 3.6 µs

C. 4.0 µs

D. 6.0 µs

34

108. In the following 8086 program given below

MOV AX, 7000 H

MOV DS, AX

MOV SI, 0200H

MOV DI, 0500H

MOV CX, 0078H

BACK: MOV AL, [SI]

MOV [DI], AL

INC SI

INC DI

DEC CX

JNZ BACK

HLT

How many times (decimal) is the DEC CX executed:

A. 78

B. 119

C. 77

D. 120

109. For the 8085 assembly language program given below

3000 MVI A, 45 H

3002 MOV B, A

3003 STC

3004 CMC

3005 RAR

3006 XRA B

3007 HLT

The content after the execution of the program is:

A. 67 H

B. E7 H

C. 45 H

D. 00 H

110. Which one of the following modes is required for 8253 to generate a square wave?

A. MODE 3

B. MODE 1

C. MODE 2

D. MODE 4

35

111. The 8086 and 8253 run at 6 MHz and 2 MHz respectively. How many numbers of T-states

are required to generate a square wave of period 0.5 ms?

A. 1000 states

B. 3000 states

C. 6000 states

D. 2000 states

112. Consider the following instruction executed in 8086 microprocessor:

LOAD X

ADD Y

STORE S1

LOAD Y

MULT X

ADD S1

STORE Z

The value stored in Z is

A. Z = X+Y+YX

B. Z = X+Y + XY+ S1

C. Z = XY+S1

D. Z = X+Y+S1

113. In a certain medium the Electric field of a propagating plane wave is given by

xyt ˆ)310cos(10E 8

V/m. The medium is

A. free space

B. a lossless dielectric

C. a lossy dielectric

D. a good conductor

114. The Polarization in a dielectric material can be written as

A. E)1(P

r

B. E)1(P 0

r

C. EP 0

r

D. )1(P 0 r

36

115. The ratio of conduction current density to displacement current density is

A.

j

B.

j

C.

j

D.

j

116. The electric field of a plane wave propagating in free space is given by )]5.0866.0([

00e)ˆAˆ5.0-(EE

yxktjyx

V/m. The value of A is

A. 0.866

B. -0.866

C. zero

D. 0.5

117. A cylindrical conductor of radius 0.5 m carries a current with uniform current density

zr ˆe4J 2

A/m2. The magnetic field inside the conductor is given by

A. φ]e2e1[r

1H 22 rr r

B. φ]e1[r

1H 2r

C. φ]e2e1[4r

1H 22 rr r

D. φ]e1[4r

1H 2r

118. For an air filled rectangular waveguide of dimensions 2.5 cm x 1.2 cm, the cut-off

wavelength of the dominant mode is

A. 2.4 cm

B. 5.0 cm

C. 2.5 cm

D. 3.7 cm

37

119. The attenuation in a typical optical fiber is 0.6 dB/km at 1310 nm wavelength. If W100

power is launched into the fiber at 1310 nm, the power (in W ) in the fiber after 10 km

will be

A. 1

B. 16.6

C. 25

D. 50

120. A wire conductor is carrying a current of 40 A. The magnetic flux density at a distance

4 cm is

A. 4 10-7

Wb/m2

B. 2 10-4

Wb/m2

C. 0.04 10-4

Wb/m2

D. 2.0 10-4

Wb/m2

121. A solenoid of 1200 turns is wound uniformly in a single layer on a glass tube of 2 m long

and 0.2 m diameter. When a current of 2 A flows through it, the strength of magnetic field

at the centre of solenoid is

A. 600 A/m

B. 6000 A/m

C. 1200 A/m

D. 2400 A/m

122. In an air filled parallel plate waveguide, the two parallel conducting plates are separated

by 2 cm. The phase velocity of the propagating mode of 6 GHz is

A. 3.3 108 m/s

B. 3.0 108 m/s

C. 1.2 108 m/s

D. 2.4 108 m/s

38

123. A charge Q is uniformly distributed over the surface of a metallic sphere of a radius R. If

is the permittivity of the medium surrounding the sphere, the E field just above the surface

of the sphere is

A. 24 R

Q

B. 2

2

4 R

Q

C. 24 R

Q

D.

Q

R 24

124. A potential difference of 10 V is maintained across the ends of a copper wire of length

2 m in the z- direction. If the mean time between collisions is 1.82 10-14

seconds, the

drift velocity of the free electrons is

A. m/s

B. m/s

C. m/s

D. m/s

125. What is the instantaneous value of Poynting vector if for a plane electromagnetic wave Ez

and Hy are given as

cos coszE a x ct and sin sinyH a x ct

A. ictxa ˆ 2sin2sin4

1 2

B. ictxa ˆ 2sin2sin4

1 2

C. jctxa ˆ 2sin2sin4

1 2

D. jctxa ˆ 2sin2sin4

1 2

126. The electric flux density in a region is given by zyxxxD ˆˆ 23

nC/m2. The charge enclosed

inside a cube of side 2 m placed centered at the origin with its sides along the axes is

A. 8 nC

B. 4 nC

C. 6 nC

D. 2 nC

39

127. A dipole antenna is to be used at the UHF of 150 MHz. The antenna length should be

A. 2 m

B. 1 m

C. 3 m

D. 1.5 m

128. The Displacement current arises due to

A. positive charges only

B. negative charges

C. time varying electric field

D. both positive and negative charges

129. A conducting sphere of radius R has charge +Q on its surface. If the charge on the sphere

is doubled and its radius is halved, the energy associated with the electric field will

A. increase four times

B. increase eight times

C. remain the same

D. decrease four times

130. The field of vector B is always

A. solenoidal

B. irrotational

C. non solenoidal

D. both irrotational and non solenoidal

131. A source delivers symbol A1, A2, A3, A4 with probability 1/8, 1/4, 1/16, 1/8 respectively.

The entropy of the system is

A. 1.5 bit per second

B. 1.5 symbol per second

C. 1.5 bit per symbol

D. 1.5 symbol per bit

40

132. If a binary PSK modulation is used for transmission, the required minimum bandwidth is

9.6 kHz. To reduce the transmission bandwidth to 2400Hz the modulation scheme

adopted should be

A. 16 – ary QASK Modulation

B. 8 – ary PSK Modulation

C. 16 – ary PSK Modulation

D. 8 – ary QASK Modulation

133. A 20 kW Carrier is sinusoidally modulated by two carriers corresponding to a modulation

index of 30% and 40% respectively. The total radiated power is:

A. 25 kW

B. 28.5 kW

C. 30 kW

D. 22.5 kW

134. 40 Signals each band limited to 5 kHz are to be transmitted over a single channel by

frequency division multiplexing. If AM-SSB modulation guard band of 2kHz is used then

the bandwidth of the multiplexed signal will be:

A. 240 kHz

B. 200 kHz

C. 280 kHz

D. 278 kHz

135. In a super heterodyne receiver, the IF is 455 kHz. If it is tuned to 1000 kHz, the image

frequency will be

A. 2455kHz

B. 1910kHz

C. 1455kHz

D. 910kHz

41

136. Match List-I (modulation) with List-II (ratio of transmitted to carrier power) and select the

correct answer using the code given below

List I List II

W. 100% AM

X. 80% AM

Y. 50% AM

Z. FM

1. 1.5

2. 1.32

3. 1.125

4. 1.00

W X Y Z

A 3 4 1 2

B. 1 4 3 2

C. 3 2 1 4

D. 1 2 3 4

137. Match List-I (communication service) with List-II (bandwidth) and select the correct

answer using code given below

List I List II

W. AM Broadcast

X. Telephone

Y. Wideband FM

Z. Television

1. 10 kHz

2. 4 kHz

3. 200 kHz

4. 7 MHz

W X Y Z

A. 3 4 1 2

B 1 2 3 4

C. 1 4 3 2

D. 3 2 1 4

138. A certain AM transmitter radiates 9 kW with the carrier unmodulated, and 10.125 kW

when the carrier is sinusoidally modulated. The modulation index

A. 0.4

B. 0.5

C.

D. 1

42

139. The situation when both transmitter and receiver have to work in tandem is referred to as

A. parallel

B. serial

C. asynchronous

D. synchronous

140. The percentage power saving when the carrier and one of the sideband are suppressed in

an AM wave modulated to a depth of 100% is

A. 83

B. 82

C.

D. 80

141. If it is required to transmit at 5 Mbps, and a bandwidth of 1 MHz is used, then the

minimum SNR required is

A. 30

B.

C. 29

D. 31

142. An input signal to a receiver is 50 µV and internal noise at the input is 5 µV. An amplifier

with a noise figure of 2, amplifies the signal to 2 V at the output. The noise at the output is

A. 10 µV

B. 1.5 V

C. 0.5 V

D. 0.4 V

143. A FM broadcast system is working at 100 MHz and a Q of 500. The bandwidth of this

system is

A. ± 200 kHz

B. ± 100 kHz

C. ± 10 MHz

D. ± 20 MHz

43

144. An AM transmitter is modulated by three sources of audio signals with m1 = 0.5, m2 = 0.7

and m3 = 0.4. The unmodulated carrier power is 50 kW. The modulated power output is

A. 68.5 kW

B. 72.5 kW

C. 104.5 kW

D. 98.5 kW

145. The superhet principle is a form of

A. frequency multiplication

B. frequency translation

C. voltage translation

D. voltage multiplication

146. An RF amplifier has an output power level of 100 mW. Its value in dBm is

A. -20 dBm

B. +40 dBm

C. -40 dBm

D. +20 dBm

147. Three voice signals having frequency range of 300-3400 Hz, are frequency division

multiplexed using 20 kHz, 24 kHz and 28 kHz analog carrier signals. The minimum

channel bandwidth of resultant FDM signal assuming 1 kHz as guard band between the

channels to avoid interference is

A. 9.3 kHz

B. 11.3 kHz

C. 2 kHz

D. 12.3 kHz

148. Satellite communication operates in which band?

A. UHF

B. VHF

C. HF

D. SHF

44

149. What is the uplink and down link frequency of GSM?

A. up link 935-960 MHz and Down link 890-915 MHz

B. up link 900-950 MHz and Down link 850-890 MHz

C. up link 600-660 MHz and Down Link 550-590 MHz

D. up link 650-710 MHz and Down Link 540-590 MHz

150. A carrier is modulated by a audio sine wave. If the carrier voltage is 4 V

and the maximum deviation is 10 kHz, then the equation of FM modulated wave

A. ( )

B. ( )

C. ( )

D. ( )

45

SPACE FOR ROUGH WORK

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SPACE FOR ROUGH WORK

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SPACE FOR ROUGH WORK

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SPACE FOR ROUGH WORK