Final Electromagnetic Examination1- 2009

Sulaimani University College of Sciences Physics Department

Final Examination 2008-2009 First trial

Electromagnetic Theorem Fourth Stage Time: 3 hours

Q1/ Answer Four of the following briefly: (a) What are the three types of current densities? Defining them mathematically? (b) Write the final integral form of Maxwell's equation and state its physical meaning. (c) What is the polar material and non-polar material? (d) What are the two important properties of electric charges? (e) What is the physical meaning of V? (8 mark)

Q2/ Let Transform

into spherical coordinate and calculate its magnitude at point 3, 4,0 . (6 mark)

Q3/ If 10 Determine the flux of

of the entire surface of a cylinder

1, 0

1. (6 mark)

Q4/ Suppose the electric field in some region is found to be , in spherical coordinates ( is constant). Find: (a) The charge density . (b) The total charge contained in a sphere of radius , centered at the origin. (6 mark)

Q5/ Use Laplace’s equation for the potential field in the homogenous region between the two concentric conducting spheres with radial & . If the 0 at , and at . (6 mark)

Q6/ A spherical conductor, of radius , carries a charge . It is surrounded by linear dielectric material of susceptibility out to radius . Find the energy of this configuration. (6 mark)

Q7/ Find the self-inductance per unit length of a long solenoid, of radius , carrying per unit length.

turn (6 mark)

Q8/ A long circular cylinder of radius carries a magnetization where is constant, is the distance from the axis, and is the usual azimuthal unit vector. Find the magnetic field due to , for points inside and outside the cylinder. (6 mark)

With best wishes Omed Ghareb

Cylindrical Coordinate:

1 1

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1

1

1

1

Spherical Coordinate: 1

1

1

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1

1

1

1

1

1

Product rules: 1 2 3 4 5 6

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