Consider a finite square well, with V = 1.2 eV outside. It holds several energy states, but we are only interested in two:

• E₁ = 1.15 eV
• E₂ = 1.1 eV

1) For E = 1.15 eV, what is the decay constant, κ, outside the well in nm^-1(i.e., where V = 1.2 eV)?

κ =

2) For E = 1.1 eV, what is the decay constant, κ, outside the well in nm^-1 (i.e.,) where V = 1.2 eV)?

κ =

3) For E = 1.15 eV, suppose the probability density at some position,x, outside the well is P(x) and the probability density 1 nm farther from the well is P(x+1 nm). What is the ratio, P(x+1 nm)/P(x), of these two probailities?

Ratio =

4) For E = 1.1 eV, suppose the probability density at some position,x, outside the well is P(x) and the probability density 1 nm farther from the well is P(x+1 nm). What is the ratio, P(x+1 nm)/P(x), of these two probailities?

Ratio =

5) If we squeeze the well (decrease L), the energies of the states will increase. What is the limiting value κ_limit of an energy state's κ as its energy approaches the top of the well in nm^-1(i.e., as E → 1.2 eV).

κ_limit =

question 1

Benjamin Corp. bonds pays an annual coupon rate of 10% on a face value of $1,000. If investors' requiredrate of return is now 8% on these bonds, they will be priced at:

question 2

A bond will sell at a discount (below par value) if:

question 3

If market interest rates ______, bond prices _________.

I. increase; increase

II. increase; decline

III. decline; decline

IV. decline; increase

I am really sorry but these are related to each other, please and please show me all the steps with clear hand writing. thanks in advance

_____________

(a) Calculate the electrical conductivity of copper if it is given that the metal has 8.5 x 10²² conduction electrons per cm³ and the mobility of a conduction electron is 35 cm².V-1.s^-1.

answer , units

(b) In an electronics project you need to construct your own inductor. The instructions for making this inductor is to “wind it from a 1.2 meter length of # 20 AWG (American wire gauge) copper wire.

(i) How thick is this wire in mm ?

(ii) What will be the resistance of your inductor ?

answer , units

____________

Q3) (i) Calculate the electrical conductivity of a piece of pure Si if it is given the number of intrinsic carriers at 300 K is 1 x 10¹⁰ cm^-3 and that the electron and hole mobilities are  μ_e = 1350 cm².V-1.s^-1  and μ_h = 450 cm².V-1.s^-1respectively.

answer, units     

(ii) Compare the conductivities between Si and Cu at 300 K as calculated from Q2 and Q3(i).         

____________

Q4) Following on from Q3, the temperature now increases to 350 K. Describe semi-quantitatively how and why the carrier concentration and the conductivity will change due to this temperature change for both these two materials (Si and Cu).

Two events are observed by inertial observer Stampy to occur a spatial distance of 15 c·s apart with the spatial coordinate of the second larger than the spatial coordinate of the first. Stampy also determines that the second event occurred 17 s after the first. According to inertial observer Philip moving along Stampy’s +x axis at unknown velocity v, the second event occurs 10 s after the first. (1 c·s = 1 light-second = unit of distance.)

a) Given Philip measures the spatial coordinate of the second event to be larger than the first, determine v.

b) How far apart spatially (in c·s) do the two events occur according to Philip?

c) Does there exist an inertial reference frame v < c in which the second event can occur before the first? Briefly explain in one sentence at most.
d) Inertial observer Kenny observes the proper time between the two events. How fast along Stampy’s +x axis does Kenny move?

(Note: Each part of this question can be done independently of any other. In part a, depending on how you solve it, you might obtain two answers as solutions of a quadratic, but one of them is extraneous, because it violates the premise in part a. If you are careful, you can avoid the quadratic at the outset, but it requires you to solve part b first.)

Basic Unix Commands

Objective:
The objective of this lab is to work with files of UNIX file system.

Procedure:
1. OpenyourUnixshellandtrythesecommands:

Ø Create a new file and add some text in it vcat > filename

• Ø View a file
  vcat /etc/passwd vmore /etc/passwd vmore filename

• Ø Copy file, making file2 vcp file1 file2

• Ø Move/rename file1 as file2 vmv file1 file2

• Ø Delete file1 as file2 vrm file

//Deletefile //Double-checkfirst

vrm -i file
Ø Counts the lines, words, characters in file

vwc file
Ø Search file for a string

v Grep lubuntu /etc/passwd v grep 'else' /etc/profile
v grep ^united ~/myFile

// List lines containing ‘lubuntu’ in /etc/passwd

//Lines containing ‘else‘ in /etc/profile

//Lines starting with ‘united’ in ~/myFile

1

• Ø Output can be redirected to a file with’>’ vls > dir.txt
  vcal 1997 > year1997

• Ø Output can be appended to a file with ’>>’ vcal 1997 > years
  vcal 1998 >> years

• Ø Concatenate two files vcat f1 f2 > fs

• Ø Input redirection (less common) uses ‘<‘ vwc < years

• Ø Combine input and output redirection vwc < years > year-counts

  *Do screenshot of each steps you have completed* ((using lubuntu))

Problem 5. The aquifer source water used by the town of Pandarwin, IL contains 32 mg/L Fe2+ and 97 µg/L arsenic, predominantly in the form of As(III). To meet the new MCL of 10 µg/L the local water utility is considering several strategies. One strategy involves adding hydrogen peroxide (H2O2) to the water. Arsenic removal occurs indirectly as a byproduct of the reaction between Fe2+ and H2O2. When H2O2 reacts with Fe2+, hydroxyl radical intermediates (•OH) are produced which can rapidly oxidize As(III) to As(V). The As(V) can then be removed by coprecipitation with and adsorption onto Fe(OH)3(s) precipitates during sand filtration. The source water is well buffered at pH 8.0 by dissolved carbonate species.

(a) Write the balanced redox reaction between Fe2+ and H2O2. Fe2+ is converted to Fe(OH)3(s) and H2O2 is converted to H2O.

(b) The treatment plant flow rate is 107 L/day. If we assume that the reaction from part (a) goes to completion as written, calculate the mass of H2O2 that will be required each day to consume all the dissolved Fe2+ in the source water entering the plant.

(c) If we assume that each H2O2 molecule generates a single ⋅OH intermediate when it reacts with Fe2+, estimate the fraction of ⋅OH intermediates that will be used to convert As(III) to As(V) in the source water. Assume that each As(III) molecule reacts with only a single ⋅OH intermediate

The program (​ stack-ptr.c​ ) implements stack using a linked list, however, it contains a race condition and is not appropriate for a concurrent environment. Using Pthreads mutex locks, fix the race condition. For reference, see Section 7.3.1 of SGG book.(Section 7.3.1 is about mutex and semaphores it does explain how to implement I'm just having a hard time finding the race condition within the code)

/*
* Stack containing race conditions
*/

#include
#include
#include

typedef int value_t;

// Node structure
typedef struct Node
{
value_t data;
struct Node *next;
} StackNode;

// function prototypes
void push(value_t v, StackNode **top, pthread_mutex_t *mutex);
value_t pop(StackNode **top, pthread_mutex_t *mutex);
int is_empty(StackNode *top);

void push(value_t v, StackNode **top, pthread_mutex_t *mutex)
{
StackNode *new_node;
new_node = (StackNode *)malloc(sizeof(StackNode));
  
new_node->data = v;
  
// mutex lock and unlock code

  
}

value_t pop(StackNode **top, pthread_mutex_t *mutex)
{
   StackNode *temp;
  
   pthread_mutex_lock(mutex);
  
// mutex lock and unlock code based on empty or full stack
  
}

int is_empty(StackNode *top) {
if (top == NULL)
return 1;
else
return 0;
}

int main(void)
{
StackNode *top = NULL;

// pthread_mutex variable declarion and verify push/pop operation for 4 inputs (5, 10, 15, 20)

  
   return 0;
}

Problem 1a: Velocity Selector: Show that with the right ratio of electric to magnetic field strength a particle of velocity v will proceed through both fields in a straight line at constant speed (hint: you will need an equation containing v. Also: what does the straight line at constant speed give you?). Assume that the angle of the velocity vector relative to the magnetic field vector is 90 degrees.

b: Show mathematically that the charge magnitude and sign do not matter.

c: Draw and label the electric field vector, the electric force vector, the magnetic field vector, the velocity vector and the magnetic force vector. Hint: start with the two force vectors. They have to add to zero. Then use the vector nature of the Eq = F(E) equation and the right hand rule to get the other vectors.) Assume that the particle is negatively charged. Use into and out of the page vector notation where necessary.

d. Explain in terms of what happens with the force vectors when the charge sign changes to allow a particle of either charge sign pass through the velocity selector at constant velocity v. In other words, explain physically why the particle charge sign makes no difference.

e. Explain in terms of what happens with the force vectors when the charge magnitude changes. In other words, explain physically why the charge magnitude makes no difference in the velocity selector.

Kit Requirements:

• Arduino Uno
• Small breadboard
• Jumper wires
• 10kΩ potentiometer
• 10kΩ resistor (x2)
• 220Ω resistor (x3)
• USB cable
• Photoresistor
• TMP36 temperature sensor
• Digital Multimeter

Lab 3a:

Procedure:

·         Watch the videos:

o   Tutorial 03 for Arduino: Electrical Engineering Basics(https://www.youtube.com/watch?v=abWCy_aOSwY)

o   Tutorial 04 for Arduino: Analog Inputs (https://www.youtube.com/watch?v=js4TK0U848I)

o   TechBits 13 - Analog and Digital Signals (https://www.youtube.com/watch?v=Z3rsO912e3I)

·         Construct the breadboard circuit and implement the program presented in the video to create an adaptable night light and detailed in Chapter 2 (pp.35-39) of your textbook.

Lab 3b:

Procedure:

This week’s lab will simulate the coffee maker heater functionality we saw in Week 1. The difference in our program and the actual coffee maker is that instead of turning on a heating element, our program will blink an LED.

·         Design a circuit and Arduino program that expands the concepts explained in Chapter 3 ( pp. 52- 59) of your textbook and accomplishes the following:

o   Blinks an LED when the temperature of a temperature sensor is at or below room temperature for more than 5 seconds

o   If the temperature exceeds room temperature for more than 5 seconds, the LED will turn off.

·