Problem 1: Consider a hollow tube of length L, radius R with a uniform charge Q
and with the z-axis as its central axis. What is the electric eld at z0 along the z-axis,
where z0 > L?
To start this problem we can use the idea that there is a line of charg
Problem 1: A 75 MHz radio wave passes from vacuum into an insulating ferrite.
Find the wavelength in vacuum, the wave speed and wavelength in the ferrite, where
K=10.0 and Km =1000.0 at this frequency.
= c/ f
= (3 108 m/s)/(75 106 /s)
=4m
v = c/ KKm
v =
Problem 1: A at coil has an 18 cm radius, 40 turns and a total resistance of 40 m.
If this coil sits in the xy-plane in a magnetic eld with a z-component that decreases at
a rate of 12 T/s (dBz /dt=-12 T/s), then what is the magnitude of the induced curre
Problem 1: Consider a long wire along the x-axis with a current of 15A in the negative x-direction.
Part a: What is the magnetic eld (vector) at the position (-5cm,4cm,0)?
0 I
The magnetic eld near a long straight current carrying wire is given by B = 2r
Problem 1: A solid, insulating sphere of radius, R, has a charge density, (r) =
r
0 (1 ( R )4 ).
Part a: What is the Electric Field as a function of radius?
This is a problem similar to what was done before only here, the charge density is
not uniform. Sy
Problem 1: Oxygen-16 is a nucleus with 8 protons and 8 neutrons. The force on
an electron due to an Oxygen-16 nucleus has a magnitude of 3.5 1014 N. What is the
distance between the electron and the Oxygen-16 nucleus?
Coulombs Law gives us
kq1 q2
.
(1)
F=
Problem 1: A solenoid has a 3 cm by 3 cm square cross-section, 225 turns and a
length of 70 cm. The current through the solenoid varies as I(t) = 5t3 4t2 10 (in
A). At t = 2 s what are the energy stored in the solenoid and the voltage across the
solenoid?
For both of these problems we want to combine Kirchos Laws, resistors in
parallel and AC circuits.
Z1 =
Z2 =
1
C
R2 +
1
2
(1)
R2 + (L)2
2
(2)
Z1 Z2
Z1 + Z2
(3)
Z=
The rst two are the impedance for the two lines. The last equation treats the two lines
like
Problem 1: When monochromatic light is passed through a diraction grating with
4500 lines/cm, the highest order bright fringe seen is m = 5. What does this imply
about the wavelength of the light? (Note that the m = 5 line is seen but the m = 6 line
is no
Problem 1: Monochromatic light of wavelength 632.8 nm falls on 2 slits separated
by 0.15 mm. On a screen a distance of 9 m away what is the smallest distance from the
center of the central maximum where the intensity is 55% of its maximum.
The intensity a
Problem 1: A 50 m long aluminum wire is connected across a 12 V battery. What
is the current density inside the wire? ( = 2.75 108 m)
IL
A
I
=
A
= JL
V
=
L
= 8.72 106
V=
J
V
J
J
Problem 2: A long wire is connected across a xed voltage. When the temperatur
Problem 1: Part a: The diagram shows a light ray passing through a slab with index
of refraction n2 submerged in a liquid with an index n1 . What are the relative values of
these indices?
The answer to this multiple choice was a. In this case n1 < n2 beca
Problem 1: Consider two concentric, conducting spherical shells of radii ra < rb .
The inner shell has charge Q and the outer shell has charge Q. What is the capacitance
between these two shells with and without an insulator with dielectric constant, K, i
Problem 1: Consider a long wire along the y-axis with a current of 12 A in the
negative y-direction. What is the force per length on this wire if it sits in a magnetic
eld of 2.5 104 T in the positive z-direction? Give the answer as a vector.
In this case