Download Answer ONE question from each unit

Regulation : 09
Code No: EE209/2
VIGNAN UNIVERSITY :: VADLAMUDI - 522 213
Vignan’s Foundation for Science, Technology and Research (Estd. U/s 3 of UGC Act of 1956)
II B.Tech III Semester Regular Examination, December, 2010
ELECTRO MAGNETIC FIELDS
(EEE)
Time: 3 hours
Max. Marks : 60
Answer ONE question from each unit
All Questions carry equal marks
***
UNIT – I
1.
12 Marks
(a)
Derive the expression for electric field intensity due to a line charge carrying uniform line
charge density PL c/m extending from a point A to point B on the z – axis.
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(b)
A point charge of 30nC located at the origin while plane y = 3 carries charge density
10 nC / m2. Find D at (0,4,3)
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(OR)
2.
(a)
(b)
Explain the applications of Gauss Law and hence obtain the expression for D due to a
point charge.
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Derive Coulomb’s law from Gauss law.
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(c)
Give D = z cos 2 a z c / m 2 . Calculate the charge density at (1,

,3).
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UNIT – II
3.
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12 Marks
(a)
Derive the boundary conditions between 2 dielectrics having dielectric constants 1 and
2 .
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(b)
Define polarization and obtain a relation between D , E and P .
(c)
Given the potential V =
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10
  
sin  cos  . Find the electric flux density D at  2, ,0 
2

 2 
4M
(OR)
4.
(a)
State and Explain Laplace’s equation.
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(b)
(c)
Derive the expression for capacitance of co-axial capacitor.
Derive the expression for energy density in Electro static field.
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UNIT – III
5.
(a)
(b)
12 Marks
State and explain Biot – Savart’s Law.
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A circular loop located on x2 + y2 = 9, z = 0 carries a direct current of 10 Amps. Along
a  . Determine H at (0,0,4) and (0,0,-4).
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Regulation : 09
Code No: EE209/2
(c) A solenoid of length l and radius r consists of N turns of wire carrying a current I. Show
nI
that at point P along its axis H =
cos  2  cos 1 a z . Where n = N , 1 and  2 are
2
l
angles subtended at P by the end of turns as shown in fig. 5(c)
(OR)
6.
(a)
(b)
Derive the expression for magnetic field intensity due to a infinite straight conductor placed
along z axis which carries a uniform line current I amps.
6M
Derive the expression for magnetic field infinite steel sheet of current using Ampere’s
circuit law.
6M
UNIT – IV
7.
12 Marks
(a)
Derive the expression for self and Mutual inductance.
6M
(b)
Determine the self inductance of a co-axial cable of inner radius a and outer radius b.
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(OR)
8.
(a)
(b)
Derive an expression for Energy density in magnetic field.
6M
2
A rectangular coil of area 10 cm carrying current of 50 amps lies on plane
2x + 6y – 3z = 7. Such that the magnetic moment of coil is directed away from the origin.
Calculate its magnetic moment.
6M
UNIT – V
9.
(a)
(b)
10.
(a)
(b)
12 Marks
Explain about Transformer and motional EMF and hence obtain the 2
equation.
nd
Maxwells
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2
A 30 cm rectangular loop rotates at 1.3 rad/sec in a magnetic field 0.06 wb/m normal to
the axis of rotation. If the loop
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(OR)
State the Maxwells equations. Write the Maxwell equations in differential and Integral
form.
8M
A conductor with cross sectional area of 10 cm2 carries a conduction current
0.25 in 109 tmA. Given that   2.5  10 6 S/m and r 6 , Calculate the magnitude of the
displacement current density.
4M
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