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Wednesday, 6 May 2015

ELECTROMAGNETIC WAVES AND TRANSMISSION LINES EMTL MODEL PAPERS JNTUH



SKYUP’S MEDIA

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING B.Tech II year – II Semester Examinations, Model Paper-1 ELECTROMAGNETIC WAVES AND TRANSMISSION LINES

Time: 3 hours
Max. Marks: 75
PART- A (25 Marks)

1.   a. State and Express the Coulomb‟s Law.
(2 M)
b. Derive the Possion‟s and Laplace Equations for electrostaticfield.
(3 M)
c. State and Express the Biot-Savart‟s Law.
(2 M)
d. Write down the Maxwell‟s Equations in word statement.
(3 M)
e. Define the Uniform Plane wave.
(2M)
f . Define the Surface Impedance.
(3M)
g. Define the characterstic impedance.
(2 M)
h. Define the phase velocity.
(3 M)
i. Define the Reflection Coefficient
(2 M)
j. Explain the losses in transmission Line.
(3 M)

PART-B (5*10=50 Marks)

2.          a. State and Prove Gauss‟s Law.
b.Let   = 400Sinθ/(r2+4) ar A/m2. Find the total current flowing through that portion of the
spherical surface r=0.8 bounded by 0.1<θ<0.3π ,0<<2π.

OR

3.          a. Show That  = ρ

b.Given The Flux density D=16/r cos(2θ)  c/m2, Find the total charge with in the region 1<r<2m, 1< θ<2rad,1<  <2π

4.          a. State The Law required to calculate magnetic flux density or magentic field intensity for a given current or current distribution and derive the expression for the same.

b.   Derive the conditions at boundary surface of Dielectric-Dielectric interface?

OR
5.          a. Define and Explain Ampere‟s circuit Law.

b.  State Maxwell‟s Equations in Differential and Integral form with clear statement

6.          a. Derive the equation for uniform plane wave in terms of H.

b.  A 100MHz uniform plane wave Propagates in a lossless medium for which  r=5 and µr=1 find vp,β,λ,Es,Hs.

OR

7.           a. State and Prove the Pointing Theorem b. Write short Notes on

i) Surface impedance ii) Brewster Angle

8.         a. Derive The Expression for Transmission Line Equation. b. Given R = 10.4 Ω/mt
L = 0.00367 H/mt
G = 0.8x10-4 mhos/mt
C = 0.00835 µF/mt.
Calculate Z0 and  at 1.0 KHz.

OR
9.          Derive the expression for α and β in terms of primary constants of a line

10.      a) Establish the relations for Zsc  and Zoc  of rf lines and sketch their variation with βl

b) A 60ohm lossless line is 30m long and is terminated with a load of 75+j50ohms at 3MHz

find its reflection coefficient,VSWR,if the line velocity is 60% of the velocity of light

OR

11. a) Explain the principle of single stub matching. b)Calculate the skin depth for the following conditions.

i) Copper f=1010Hz,µ=µ0, σ=5.8x107s/m





SKYUP’S MEDIA

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING B.Tech II year – II Semester Examinations, Model Paper-2 ELECTROMAGNETIC WAVES AND TRANSMISSION LINES

Time: 3 hours
Max. Marks: 75

PART- A (25 Marks)

1. a. Define Electric Potential and Ploarization
(2M)
b. Define Capacitance? Explain different types of capacitances
(3M)
c. State and Express the Amperes circuit Law
(2M)
d. Define the boundary condition? Give the relations for electric field
(3M)
e. Define Brewster Angle
(2M)
f. Define Polarization? Explain different types of polarization
(3M)
g. Define the Propagation constant in terms of primary constants
(2M)
h. Define the group velocity
(3M)
i. Define the stub?
(2M)
j. Write down the Applications of Smith chart
(3M)

PART-B (5*10=50 Marks)

2.a. State
and prove the coulomb‟s law ?

b.  Find the force on a charge of -100mC located at P(2,0,5) in free space due to another charge 300µC located at Q(1,2,3).

OR

3. a. State and Prove  Laplace‟s and  Poissson‟s Equation Starting from Gauss‟s  Law
b. The potential field V=2x2yz-y3z exists in a dielectric medium having ε=2ε0  calculate
.                the total charge within the unit cube 0<x<1m,0<y<1,0<z<1m.

4.    a. Define Ampere‟s Circuit Law in point and integral forms for Static fields.

b. Establish the fields in the different regions of a coaxial cable carrying a current I, and sketch their variation with radial distance.

OR

5. a. State and Prove Boundary condition between Dielectric-Dielectric

b. A Potential field is given by V=15(x2-y2).The point p(4,-2,1) lies on the boundary of the conductor and free space At P, obtain the magnitudes of i) V ii) E iii) EN iv) Etan v)D vi) ρs


6.  a. Derive The attenuation and phase constant in conducting medium
b. At 50MHz, a lossy dielectric material is characterized by ε=3.6ε0, µ=2.1µ0 and σ=0.08S/m. If Es=6e-ϒxazV/m, compute i) ϒ ii) λ iii) u iv)η v) HS
OR

7. a. Derive Expression for reflection and transmission coefficients of an EM wave when it is incident normally on a dielectric

b. A perpendicularly polarized wave is incident at an angle of өi=15degrees. It is propagating from medium1 to medium2 .medium 1 is defined by εr1=8.5,μr1=1,σ1=0 and medium 2 is free space if Ei=1mv/m, determine Er, Hi, Hr

8. a. Derive The Condition for Distrotionless Transmission Line

b. Measurements on a Transmission Line of length 120Km were made at frequency of 6000Hz.If ZOC=520(-30deg) and ZSC=640(43deg) find Zo and P.

OR

9.  a. Derive The Basic Transmission Line Equation

b. The propagation constant of a lossy transmission line is 1+j2 m-1 and its characteristic impedance is

20+j0Ω at ω= 1rad/s. Find R,C,L,G for the Line.

10. a. Derive the relation between reflection coefficient and characteristic impedance b. Write short notes on smith chart

OR

11.   A transmission line of length 0.40λ ? has a characteristic impedance of 100Ω and is Terminated in a load impedance of 200 + j180ω. Find the

(a)  Voltage reflection coefficient
(b)  Voltage standing wave ratio

(c)  Input impedance of the line.


SKYUP’S MEDIA

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING B.Tech II year – II Semester Examinations, Model Paper-3 ELECTROMAGNETIC WAVES AND TRANSMISSION LINES

Time: 3 hours
Max. Marks: 75

PART- A (25 Marks)

1.a.Define Electric field and
Electric flux Density
(2M)
b. Define Electric dipole? Differentiate between polar and non polar dielectrics
(3M)
c. State and Express the Stokes Theorem
(2M)
d. Write down the Maxwell‟s equations in free space condition
(3M)
e. Define Skin depth or Depth of penetration
(2M)
f. State and Express the Poynting theorem
(3M)
g. Write down the Distortionless Line
(2M)
h. Define Transmission line? Explain different types of Transmission lines
(3M)
i. Define the voltage Standing Wave Ratio
(2M)
j. Difference between the single stub matching and double stub matching
(3M)
PART-B (5*10=50 Marks)

2. a. Define Line charge Density? Derive the infinite line Electric field E=ρL/2
aρ
b. Find E at(2,0,2) if a line charge of 10PC/m lies along the y-axis


OR

3.  a. Define Capacitance and obtain the parallel plate capacitance

b.  A parallel plate capacitance has 500mm side plates of square shape separated by
10mm distance A sulphur slab of 6mm plates with εr=4 kept is on the lower plate find the capacitance of the set up If a voltage of 100V is applied across the

capacitor calculate the voltages at both the regions of the capacitor between the plates.


4 .a. Derive an expression for magnetic field strength,H,due to a finite filamentary conductor carrying a current I and placed along Z-axis at a point „P‟ on Y-axis. Hence deduce the magnetic field sgtrength for the length of the conductor extending -∞ to +∞.

b. State and Prove Biot-Savart‟s Law.

OR

5.a.What is the inconsistency of Ampere‟s Law
b.A certain material has σ=0 and εr=1 if H=4sin(106t-0.01z) A/m.Make use of

Maxwell‟s equations to find µr.

6. a. Show that E and H are perpendicular to each other inphase and the ratio of their Magnitudes is a constant for a uniform plane wave.

b.  A uniform plane wave at a frequency of 1GHz is travelling in a large block of teflon

εr=2.1,µr=1 andσ=0. Determine ϒ,η,β,λ.

OR

7.  a. Define Polyting's theorem and Polyting Vector.
b.  A Sinsoidally varying EM wave in a medium of εr=1 µr=1 is transmitting power at a density 1.2watts/m2 .Find the maximum values of E and H fields.

8.Explain the conditions which are used for minimum attenuation in transmission lines

OR



10.a. Derive the expression for the input impedance of a transmission line of length L. b. List out the applications of transmission lines

OR

11 .Describe the construction of smith chart and give its applications.




SKYUP’S MEDIA

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING B.Tech II year – II Semester Examinations, Model Paper-4 ELECTROMAGNETIC WAVES AND TRANSMISSION LINES

Time: 3 hours
Max. Marks: 75
PART- A (25 Marks)

1.a. State and Express the Divergence theorem
(2M)
b. A charge of 10PC is at rest in free space.Find the potential at a point,
A 10cm away from the charge.
(3M)
c. A magnetic field, H=3ax+2ay,A/m exists at a point in free space, what is the
magnetic flux density at the point
(2M)
d. Explain the different types of medium
(3M)
e. Define the Good Conductor
(2M)
f.Differences between intrinisic impedance and surface impedance
(3M)
g. Define the characterstic impedance in terms of the open circuit and short circuit
impedance
(2M)
h. Define and Explain the infinite Line
(3M)
i. Define the smith chart
(2M)
j. Write down the relation between reflection coefficient and voltage standing wave
ratio
(3M)
PART-B (5*10=50 Marks)

2.a .State coulomb‟s and derive the expression for coulomb‟s law to calculate the magnitude of The force between two charges

b. Prove the poisson‟s equation for Electrostatic field

OR

3.a.Distinguish between the conduction and convention currents. Establish the current Continuity equation and hence calculate the relaxation time for brass material, having Conductivity of 1.1x107mho/m at 10MHz.

b.Find the capacitance of a 50cm.long coaxial cable, having conductors of 4cm and 2cm diameters, separated by a medium of a relative permittivity 2.56.

4.a.Define Inductance?  Derive the toroid inductance

b.A toroid has air core and has a cross-sectional area of 10mm2.It has 1000turns and its mean radius is 10mm.Find its Inductance



OR


5.a. Obtain the integral form of Maxwell‟s equation from Amperes circuit law in the

generalized form

b.  In a medium of µr=2, find E,B and displacement current density if H=25sin(2x108t+6x)  mA/m

6.  a. For good dielectrics derive the expressions for α,β,ϒ,η
b. A plane wave travelling in a medium of εr=1,µr=1 has an electric field intensity of

v/m.Determine the energy density in the magnetic field and also the total energy density.

OR

7.   a Derive Expression for reflection and transmission coefficients of an EM wave when it is incident normally on a dielectric.
b.A perpendicularly polarized wave is incident at an angle of өi=15degrees. It is is free propagating from medium1 to medium2 .medium 1 is defined by εr1=8.5,μr1=1,σ1=0 and medium2 space if Ei=1mv/m, determine Er, Hi, Hr.


8.a.Derive the attenuation constant and phase constant in terms of primary constants b.Explain different types of loading for transmission lines.

OR

9.a.Derive the characteristic impedance of a transmission line in terms of its line constants b.At 8MHz the characteristic impedance of a transmission line as 40-j2ohms and the

propagation constant 0.01+j0.18 per meter.Find the primary constant.

10. Explain the principal of single stub matching

OR

11.  a. Derive the relation between reflection coefficient and characteristic impedance b. write short notes on smith chart.







SKYUP’S MEDIA

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING B.Tech II year – II Semester Examinations, Model Paper-5 ELECTROMAGNETIC WAVES AND TRANSMISSION LINES



Time: 3 hours                                                                                             Max. Marks: 75


PART- A (25 Marks)

1.a.The force F=2ax+ay+az N, is acting on a charge of 10C, find the electric field

Intensity,its magnitude and direction.
(2M)
b.The current density J=1/r2(cosӨar+sinӨ   ),A/m2, find the current passing

through a sphere radius of 1m
(3M)
c.Given magnetic flux density,B=ρ   ,find the total flux crossing the surface

1<ρ<2m and 0<z<5m.
(2M)
d. Define Current? Explain different types of Current Density
(3M)
e. Define The Good dielectric
(2M)
f. Define Skin Depth
(3M)
g. Define the Loading of Line
(2M)
h. Define and Explain infinite line
(3M)
i. Define the Stub
(2M)
j. Define the reflection coefficient and standing wave ratio
(3M)
PART-B (5*10=50 Marks)
2.a. State and Explain Coulomb‟s law.

b. Three point charges Q1=0.5nC,Q2=0.4nC, Q3=-0.6Nc are located in free space at(0,0),(3,0)and(0,4)respectively.Determine the potential,electricfield intensity and flux density at (3,4).

OR

3.  a. Determine the amount of work necessary to assemble three point charges Q1, Q2,Q3 in an empty space. Extend your result to n-point charges.

b.  Show that  = ρ .
4.    a. State and Prove the Ampere‟s Force Law.

b.A toroidal ring has 200turns. The outer diameter of the ring is 15cm with the inner diameter of 12cm.Find the flux density if the current is 8A.

5.  a. State and explain boundary conditions between two dielectric media.

b.  A circular loop conductor having radius of 0.2m is placed in XY plane. The loop consists of a resistance of 10ohms. If the Magnetic field is B=Sin104t
Tesla, find the current flowing in the loop.

6. a.Discuss the significance of pointing theorem and derive the equation for pointing Vector.

b.A vertically polarized uniform plane wave is incident at an angle of 450 from air on a dielectric slab of ϵr=4,µr=1 and σ=0.the incident field strength is 100mV/m at 10MHz.Calculate the power transmitted to the dielectric slab Find the angle of incidence for which angle of reflection is zero.

OR
7.a.Derive the equation for uniform plane wave in free space condition.
b.The electric field in free space is given by E=50cos(108t+βx)ayV/m.Find the direction of wave propagation.Calculate β and time it takes to travel a distance of λ/2

8. Derive the equation for input impedance of the Eighth-Wave(λ/8) line? Explain Its significance

OR

9.    Write Short notes on
i)  Smith Chart
ii)   Single stub matching

10.a.Derive an expression for the propagation constant and characteristic impedance of Transmission line with R,L,C,G.
b.  A telephone line has R=30Ω/km, L=100Mh/km, G=0,C=20µF/km. At f=1KHz,obtain i) Z0

ii)   propagation constant iii ) phase velocity

OR

11.a. Derive an expression for the input impedance of a lossless line of length „l‟ in
Terms of  Z0,  β,ZL and l when terminated by a ZL load.

b. A lossless transmission line length „l‟ with Z0=50 is terminated by a load of ZL=50+j50.Determine the reflection coefficient “Rr” and the standing wave

Ratio.

.



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