This document appears to be an exam for an electromagnetics course consisting of 3 questions worth 30, 50, and 20 marks respectively. Question 1 involves calculating the energy expended to move a charge between two points in an electric field, and the potential difference between those points. Question 2 involves a parallel plate capacitor and calculating: the potential between the plates by solving Laplace's equation, the electric field between the plates, the electric flux density, the surface charge densities, the capacitance using charge and potential, and the total energy stored using two different methods. Question 3 involves finding the magnetic field H given a thin cylindrical conducting shell of radius a carrying a current I.

1. de
Philadelphia University Student Name:
Faculty of Engineering Student Number:
Dept. of Electrical Engineering
Second Exam, Second Semester: 2018/2019
Course Title: Electromagnetics I Date: 1/5/2019
Course No: (610213) Time Allowed: 50 Minutes
Lecturer: Dr. Mohammad Abu-Naser No. of Pages: 3
Question 1: (30Mark)
Objectives: This question is related to electric potential and work
In an electric field
ˆˆ20 sin 10 cos V/mE r r rθ θθ= +
v
1) Calculate the energy expended in transferring a 10 nC charge from point
( , , ) (5,30 ,0 )A r φ θ = ° ° to point ( , , ) (10,30 ,60 )B r φ θ = ° °
2) Calculate the potential difference between A and B VAB
1
Form No. T611

2. Question 2: (50Mark)
Objectives: This question is related to parallel plate capacitor
The conducting plates of parallel plate capacitor placed at 2mz = − and 2mz = are
maintained at potentials of 0 and 200 V, respectively. If the surface area of each plate
is 1000 m2
and that the plates are separated by air. Calculate:
1) The potential between the plates by solving the Laplace equation
2) The electric field between the plates through E V= −∇
v
3) The electric flux density between the plates
4) The surface charge densities at the plates ρs
5) The capacitance using /C Q V=
6) Total energy stored in the capacitor using
21
2
E dvε∫∫∫
7) Total energy stored in the capacitor using
21
2
CV
2

3. Question 3: (20Mark)
Objectives: This question is related to Ampere’s law
A thin cylindrical conducting shell of radius a, infinite in length along the z axis,
carries a current I. Find H
v
in all regions.
3
I
a