Pre-Memorial Day BBQ @ CIE-SoCal Young Engineers and Scientists Professional Forum 5/24/2014

After FAILing our Exam2, the entire class decided to attend the CIE-SoCal 2014 Young Engineers and Scientists Professional Forum....  We asked numerous questions to those graduated professionals about the "real world" career experiences they encountered.  Including Internships, Resume, Interview strategies, and Job cultures...etc.

Welcome to the Founders Hall

First session in progress...

Guests from various big companies

 Group photo time!

Of course, last but not least, BBQ time~ (Prof Mason showed us he is indeed, made out of Hotdogs!!)

Eddie, Rudy.....

Elias......

Prof Mason preparing the meat patties

Finally, HOT DOGS!!!

Dogs are up!!!

Dropped Hot dog for Prof Mason's dog

What a nice overcasy day

Eating and chatting with special guests 

Prof Mason's wife

DOGS ON FIRE!!

Matt, Mark.........

Sadly, my friend is graduating her Ph.D the same day at 1:00PM and I had to ditch my folks for the second half of session.

HAPPY MEMORIAL DAY EVERYONE!!!  :)

Electromagnetic Induction 5/19/2014

Today we started the idea of electromagnetic induction.  Our first lab of the day was to measure the magnetic field of a solenoid.  we did this by a looping a current carrying loop over a hollow plastic tube with multiple loops.

Holding the loop in place via the hollow tubing to position the sensor of the sensor probe in line with the wire loop. 

Gradually increasing the number of loops, we discover the magnitude of the relationship of the coils as magnetic field goes up.  Each trial we logged the data using a magnetic field tube sensor via Logger Pro 

As shown 1 loop) top left 2 loops) top right 3 loops) bottom left 4 loops) bottom right.   After each collection, we eased the power off a few seconds to obtain a zero reference.

We used our logged data to calculate the magnetic fields by obtaining averages using the statistics function in LoggerPro.  We took the mean of the magnetic field of A (when the power was on going through the wire) subtracted by the mean of B (when the power turned off) to calculate the averages.   For Graph 1 above, we obtained our experimental value of 0.014 mT.  For Graph 2, 0.023 mT.  For Graph 3 0.027 mT.  For Graph 4 0.044 mT.

Our values we measured during the experiments was discarded due to the inconsistency.  We conclude that the uncertainty was due to the orientation of the sensor.  It was extremely difficult to get it perfectly aligned due to the high sensitivity.

Instead, we used nice values measured by Prof Mason because he broke(made hole) on the tube LOL.

EPIC FAIL

Next, we were given a coil of wire connected it to a galvanometer to experiment with ways that affected the needle the most by using a bar magnet in this experiment:

Factors such as the number of coils and the velocity in which we moved the magnet in and out of the coil contributed to the amount of current we measured.

Next, electromagnetic induction wirelessly just like cell phone chargers!  The BIG RED puppy was able to emit an electric magnetic so strong that it was sufficient to lit a light bulb without contact!

Prof Mason's new toy!!  tsk tsk tsk look at that beauty!!

We ended the class with a demonstration performed by Prof Mason as a current was provided to a driver coil and it was induced inside the smaller coil. The result was that the voltage induced in a smaller coil was smaller.

More on Magnetic Fields Prof Wolf 5/14/2014

Today we had a sub.... Professor Wolf!!  He's super cool we get to take three breaks instead of just one...  After the fiesta, we started a lecture of the Biot Savart Law, an equation describing the magnetic field generated by an electric current.

 Biot Savart Law of an infinite long uniform wire

Our group derivation about the center of a current-running square 

Biot Savart Law of a point at the origin of an uniform ring

Our group derivation by Dez about the center (left) about the edge (right)

Fan-shaped derivation as parallel components at each ends cancel out

Our first lab of the day involves the way to measure Earth's magnetic field inside our classroom:

The magnetic field of the earth was experimentally determined by applying a current to a coils and using the coils magnetic field. B(coil)=ulN/2R=B(earth)tan(theta). For B(coil) was determined Biot-Savart Law and a graph of the B(coil) vs tan(theta) created a slope that represents B(earth). The angle made when the current was applied was used to calculate tan(theta).

 Eath Magnetic Field Lab instructions 

Lab result including the experimental set up. 

After fitting the equation to our plotted points we observed that the magnetic field of the earth is approximately 2.83*10^-5 T.  As seen in the graph, our magnetic fields from each trial were not far to the order of Earth's magnetic field range from 25 to 65 microtesla.  Our major source of error was the angle theta used and the interference of Building 60's metal structure.

Next, more derivation of Biot Savart Law involving a point a distance away from a ring

Prof Wolf demonstrate the direction of the force vector by applying the right-hand rule

Then, we were introduced to the solenoid, a stack of current loops

Derivation of solenoid formulas

Prof Wolf measured the magnitude of the magnetic field inside springy solenoid coil spread out and connected to an energy source to provide it with a current.  By using a probe with Logger Pro, 

Last, we observed that the direction of magnetic field within the solenoid is equal to the solenoid's vector magnetic moment for a single current-carrying loop. The field is strongest at the center of the solenoid and drops off near the ends.  Due to this solenoid length in comparison to its diameter, it is long and the the magnetic field at each end is half as the magnitude at the center, as shown by Prof Wolf.