BASIC EQUATIONS OF ELECTRODYNAMICS
Maxwell's Equations
In free space:
1
=
0
=
t
=0
= 0 J + 00
t
7
(mass of the electron)
Spherical
x = r sin cos
y = r sin sin

PHYB21- 2014
Practice problems
Q1: (a) Show that:
(b)
Q2: Two large parallel conducting plates a distance d apart are charged
with a surface charge density s, see the figure
c) What is the potential difference between the two plates in this case?
Answer:

Topic 5
Vector Operators: Grad, Div and Curl
In the rst lecture of the second part of this course we move more to consider
properties of elds. We introduce three eld operators which reveal interesting
collective eld properties, viz.
the gradient of a sca

CYK\2009\PH102\Tutorial 10
Physics II
1. [G 6.3] Find the force of attraction between two magnetic dipoles,
distance
r
apart, (a) using
F = 2IRB cos ,
2. [G 6.8] A long circular cylinder of radius
distance from the axis, and
R
and (b) using
m1 and m2 ,
(m

2. Calculate
(|r|2 ) and
3. Calculate
(|r|) and
4. Show that
5
(
2
2
(|r|2 ).
[Answers:
(|r|).
2xi + 2yj + 2zk = 2r
r
|r|
[Answers:
and
and
6.]
2
.]
|r|
) = 0.
Vector derivatives in non-Cartesian coordinates
In this section, we will learn how to deal wit

PHYB21- 2014
Sample Solution Assignment-3
Q1: (5 points)
Q2: (5 points)
Q3: (10 points)
If = 0 we correctly obtain zero field. If = / 2 we obtain
In this case we simply have a flat disk with radius L , and this is indeed the field at the cente

PHYB21- 2014
Feb 26 2014
Assignment-2
Q1: A- Consider a hollow spherical conductor placed in a uniform horizontal
electric field.
i. Sketch the electric field lines everywhere. How the charge on the surface
of the conductor is distributed?
ii. How does th

PHYB21- 2014
Due Date: April 3 2014
Assignment-5
Q1:
!
!
The magnetic vector potential A , is given by A( , , z) = 2 / 4 z Wb/m. Calculate the
total magnetic flux crossing the surface, = / 2 , 1 2 m, 0 z 5 m. Solve this
problem in two different ways (Hint

PHYB21- 2014
Sample Solution Assignment-4
Q2: (10 points)
But we know that
This means that
Replacing the term in the expression for m amounts to keeping only the z-component.
Making use of this fact, along with writing out the da element gives,
Q3: (10 po

PHYB21- 2014
Sample Solution Assignment-5
Q2: (10 points)
Q3: (10 points)
(a) First we can find the magnetic field at a point a distance z along the axis due to a
circular loop of radius b. This can be shown to equal
The flux through the little loop (of r

PHYB21- 2014
Sample Solution Assignment-2
Q2: (10 points)
A-
B-
C-
D-
Q3: (10 points)
Refer to the figure to find the position vector of the charges
This can be written in a more elegant way using the d

PHYB21- 2014
Due date: one week after posting
Assignment-1
Q1: Review of vector Calculus:
A-
B-
Verify the differentiation formulae (the here represents the time derivative)
Q2:
A-
B-
i-
ii -
C-

PHYB21- 2014
March 14 2014
Assignment-3
Q1:
A current / flows down a wire of radius a.
(a) Assume the current is uniformly distributed over the surface, what is the surface
current density K ?
(b) Now, if it is distributed in such a way that the volume cu

Review Material for Quiz, Test & Exam
PHYB21, Winter-2014
These questions were designed to help you understand the fundamental
concepts discussed in class. Think about them well after you did your study.
Before you discuss them with your colleges, try to

PHYB21- 2014
Due Date: March 26 2014
Assignment-4
Q1:
Find the force on the triangular loop shown in figure. Both loops carry a current
I. How the force would be if the triangle was replaced by a square loop.
Q2:
The magnetic dipole moment may be writt