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Seat No.: Enrolment
GUJARAT TECHNOLOGICAL UNIVERSITY
PDDC- SEMESTER-III EXAMINATION SUMMER 2017
Subject Code: X31102 Date:29/05/2017
Subject Name: Engineering Electromagnetics
Time: 02:30 PM to 05:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1

Define the terms: scalar, vector unit vector. Also explain spherical coordinate system with neat clean diagram in brief.
07

Solve the followings:
Show that the vector fields A ρcos(Ø)aρ ρsin(Ø)aØ ρaz and B ρcos(Ø)aρ ρsin(Ø)aØ ρaz are everywhere perpendicular to each other.
Transform the given vector G ax into cylindrical coordinate components variables.
07
Q.2

Derive the expression for the electric field intensity due to an infinite sheet charge ρs C/m2 in yz plane at any point on the x axis.
07

Define electric field intensity. For given infinite uniform line charges of 5 nC/m lie along the positive and negative x and y axis in free space. Find E point
07
OR

Define the term volume charge density. Three infinite uniform sheets of charge
are located in free space as follows: 3 nC/m2 at z 6 nC/m2 at z 1
nC/m2 at z 4. Find E at the point P
07
Q.3

Explain the concept of potential gradient and derive the relationship between E and V.
07

Define current density. Evaluate point form of the continuity equation.
07
OR
Q.3

Define the divergence of a vector field. And prove the divergence theorem.
07

Define dipole and dipole moment. Determine the V and E for a dipole of moment p=6 az nC.m located at the origin in free space at point
07
Semi infinite planes at Ø 0 Ø are separated by an infinitesimal insulating gap.If V 0 at Ø 0 V 100 at Ø calculate potential V electric field intensityE.
Q.4

Derive the Poisson's equations Laplace's equations. Also explain uniqueness theorem.
07

Determine the Electric field intensity at point for the field of two coaxial cylinders, 50 V at 2 m and 20 V at 3 m.
07
OR
Q.4

Derive the boundary conditions for the perfect dielectric materials.
07

State Bio-Savart law derive the expression for the magnetic field intensity if
Infinitely long wire carrying current I located on the z axis.
07
Q.5

State prove poynting theorem relating to the flow of energy at a point in space in and electromagnetic field.
07

Write a brief note on retarded potential.
07
OR
Q.5

State Maxwell's equations in point form and explain physical significance.
07

Write a brief note on wave propagation in good conductor.
07