Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
Homework4
1
Name:
Problem 1: Surface charges on capacitors (Livingston 33)
a) A voltage of 9 volts is applied acoss an empty capacitor with plates of 10 cm 2 area separated by a
distance of 3 mm. What is the electric charge on the capacitor plates?
b) A
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
North Carolina State University
MSE355 Spring 2016. Electrical, Magnetic and Optical Properties of Materials
Homework 4 Key
Problem 1: Surface charges on capacitors: maximum 4 points
a)
C a= 0
A
d
q a=C a V a = 0
A
V =2.655 1011 C
d a
b) Compared to part
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
North Carolina State University
MSE355 Spring 2014. Electrical, Magnetic and Optical Properties of Materials
Homework 4 Key
Problem 1:
( H )=0
(
J+
D
=0
t
)
J =
J=
( Dt )
( . D)
t
Substitute . D= :
J=
t
Problem 2:
a) = 2 = 3.14e15 Hz
= c/ = 6e7 m
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
North Carolina State University
MSE355 Spring 2016. Electrical, Magnetic and Optical Properties of Materials
Homework 6 Key
Problem 1: The Photoelectric Effect (max 3 points)
Take c = 2.998e8 m/s. And me = 9.109e31 kg.
a) Fastest electron has: kinetic en
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
Homework1
1
Due1/20/16
Name:
Problem 1: General Electrostatics Review
a. A copper penny (Z = 29) has a mass of 3 g. What is the total charge of all the electrons in the
penny?
b. Use Coloumbs law and Newtons law of gravity to compute the ratio of the elec
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
North Carolina State University
MSE355 Spring 2016. Electrical, Magnetic and Optical Properties of Materials
Homework 7 Key
Problem 1: Photon and Particle Waves (Livingston 84)
a. a photon of 50 eV = 8.011e18 J energy:
+ Velocity v = 2.998e8 m/s.
+ Mome
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
Topics Covered
1. Real and imaginary dielectric constant
2. Sources of polarization
3. Light absorption in an insulator (BeerLambert)
4. Other lightmatter interactions (diffraction, scattering, reflection,
transmission)
5. Failures of classical physics
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
North Carolina State University
MSE355 Spring 2014. Electrical, Magnetic and Optical Properties of Materials
Homework 2 Key
Problem 1: Resistivity in a Lamellar structure (Livingston CH1 Problem 17)
1
1 1
= +
R e R1 R 2
a) Effective resistivity when conn
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
North Carolina State University
MSE355 Spring 2016. Electrical, Magnetic and Optical Properties of Materials
Homework 1 Key
Problem 1: General Electrostatics Review
a) Copper: MCu = 63.546 g/mol, m = 3g N = m/MCu*NA = 3/63.546*6.022*1023 = 2.843*1022
(ato
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
Homework7
1
Name:
Problem 1: Photon and Particle Waves (Livingston 84)
Calculate the velocity, momentum, and wavelength of the following objects:
a. a photon of 50 eV energy,
b. an electron accelerated through 50 volts,
c. an particle accelerated throug
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
Homework6
1
Name:
Problem 1: The Photoelectric Effect (Livingston 82)
We perform the photoelectric experiment on a sample of tantalum, for which the barrier to electron
escape from the surface (work function) is 4.2 eV. We use light of 150 nm wavelength
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
Homework5
1
Names:
Problem 1: Plane wave in NaCl crystal (Livingston 41)
A plane wave of orange light ( = 5 10 14 Hz), polarized with an electrid field amplitude 3 10 4 V/m in
the xdirection, enters a crystal of NaCl (whose index of refraction squared
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
Homework3
1
Name:
Problem 1: Derivation of the equation for charge conservation (Livingston 21)
The divergence of a curl is zero. From that and Maxwells equations, derive the following equation:
= J
t
where is the local density of electric charge (in C/m
Electrical, magnetic, and optical properties of materials
MSE 355

Spring 2016
North Carolina State University
MSE355 Spring 2016. Electrical, Magnetic and Optical Properties of Materials
Homework 5 Key
Problem 1: Plane wave in NaCl crystal (Livingston 41) (max 2 points)
a)
14
Frequency: independent of environment, =5 10 Hz
15
Angu