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Reg.No:
SNS College of Technology,Coimbatore-35.
(Autonomous)
B.E/B.Tech- Internal Assessment -I
Academic Year 2016-2017(Even)
Electronics and Communication Engineering
EC208 – Electromagnetic Fields
Time: 11/2 Hours
A
Maximum Marks: 50
Answer All Questions
PART - A (5 x 1 = 5 Marks)
1.
The force between two charges is 120 N. If the distance between the charges is
doubled ,the force will be
(a) 60N
(b) 30N (c) 40 N (d) 15N
2.
The lines of force due to charged particles are
(a) always straight
(b) always curved
(d) sometimes straight
3.
A dielectric material must be
(a) resistor
4.
(c) sometimes curved
(b)insulator
(c) good conductor
(d) semi conductor
Which of the following is not a vector?
(a) Linear momentum
(b) Angular momentum
(c) Electric field
(d) Electric potential
5.
Unit of relative permeability is
(a) Coulomb
(b) Henry (c) Henry/meter
PART – B
(d) It is dimensionless
(5 x 2 = 10 MARKS)
6.
Define Cross or Vector product.
7.
State coulomb’s law.
8.
What is polarization?
9.
List the coordinate systems used in electromagnetic engineering.
10.
Write down the need for duality of current density.
1
PART – C (14+14+7=35 Marks)
11.
a)
State and prove Gauss law and explain its applications.
14
b)
12.
(or)
Determine the electric field intensity due to an infinite line charge having
uniform charge density of ρL c/m at any point p.
a) Derive the boundary conditions of the normal and tangential components of
electric field between
(i) Dielectric and dielectric
(ii) Conductor and dielectric
(iii) Conductor and free space
(or)
b) The capacitance of a condenser formed by two parallel metal sheets, each
100cm2 in area separated by a dielectric 2mm thick is 2x 10 -4 micro farad. A
potential of 20kV is applied. Find (a) the electric flux, (b) potential gradient,
(c) the relative permittivity of the material, (d) the electric flux density
13.
14
14
14
a) State and explain Divergence theorem and Stokes theorem.
7
(or)
b) Deduce the expression for the energy stored in charged distribution
7
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PREPARED BY
VERIFIED BY
2
HOD