Final Electromagnetic Examination2- 2009

Sulaimani University College of Sciences Physics Department

Final Examination 2008-2009 Second trial

Electromagnetic Theorem Fourth Stage Time: 3 hours

Q1/ Chose the correct answer for each of the following: 3,4, 1 , which of these is incorrect? (c)

1- At Cartesian point (a)

√26

(b) 2- The component of 6 (a)

2

3

(b) 2

along 3 (c) (d)

3- Which of these is correct? (a) A A |A| (b) A · B · C

10

(d) 7.08

5- Which of the following is zero? (a)

(c)

(b)

(d)

(b)

is:

B A a

0

80, its permittivity is: (c) 79

F/m

6- If a vector field (a) · 0

4

/

(c) A B (d) a · a

B·C·A

4- If a material has (a) 81 (b) 1.10

5

(d)

10

F/m

is solenoidal, which of these is true? (c) · 0

0

(d)

0

7- Which of the following describe the sensitivity of the material to the electric field: (a) Permittivity (c) Susceptibility (b) Permeability 8- In magnetostatic field the (a) Charge density (b) Conduction current density

(d) Dielectric constant H is equal to a physical quantity named: (c) Conductivity (d) Displacement current density (8 mark)

1

Q2/ A hollow spherical shell carries charge density the electric field in the three regions: (a) (b) (c)

/

in the region

. Find

(6 mark)

Q3/ Check the divergence theorem using the function: 2 2 over the unit cube situated at the origin. (6 mark)

Q4/ A total charge of is uniformly distributed over a circular disk of radius ( ). Find the potential at a distance above the center of the disk. (6 mark)

Q5/ A rectangular pipe, running parallel to the x-axis ∞ ∞ , has three grounded metal sides, at 0, , and 0, the fourth side, at , is maintained at a constant potential . Use Laplace’s equation to find the potential within the pipe. (6 mark)

Q6/ A metal sphere of radius , carries a charge . It is surrounded out to radius , by linear dielectric material of permittivity . Find the polarization and bound charge of this configuration. (6 mark)

Q7/ What current density would produces the vector potential coordinates?

in cylindrical (6 mark)

Q8/ Calculate the energy stored in the toroidal coil with rectangular cross section (inner radius , outer radius , height ), which carries a total of turns. (6 mark)

With best wishes Omed Ghareb

2

Cylindrical Coordinate:

1 1

·

1

1

1

1

Spherical Coordinate: 1

1

1

·

1

1

1

1

1

1

Product rules: 1 2 3 4 5 6

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3

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