12-4-2014 AC RLC Circuit

     This is a sample of the graphs we obtained through use of the voltage and current sensors hooked up into our RC circuit. In order to obtain RMS values for voltage and current, we simply took the maximum value and divided it by the square root of two. We then divided the RMS voltage by the RMS current, which gave us a value of reactance. 

In lab, we conducted an experiment in which we calculated a theoretical capacitive reactance and then used current and voltage sensors to construct graphs using LoggerPro that would be used to determine RMS voltages and currents. These voltages and currents would be used to acquire another value of capacitive reactance that we would compare to our theoretical value. We did this for two different capacitors and then found that doubling the frequency greatly reduced our percentage error. We attempted a similar process with an inductor, but found that our results we not nearly as accurate as they were with the capacitor. Also, we simply ran out of time to complete the inductor experiment in its entirety.  

12-2-2014 Induction

This is a calculation for inductance, 

This is a comparison of one theoretical induction value versus an experimental one. there is a large amount of difference.

     In addition to answering a number of questions on the ActivPhysics website on Wednesday, we conducted in an experiment in which we were to determine the inductance of the coil in the above picture. We calculated the inductance by using the dimensions of the coil and also by using the oscilloscope to estimate the half time of exponential decay. 

11-25-2014 electromagnetic induction

In this experiment a galvanometer is attached to a coil to assist in measuring the induction. The voltage is induced when a magnet it run through the coil at different speeds. This shows the relationship between a magnetic field, the change in the position oof the magnet and the current in the wire.

There is a wire wrapped around this tube in order to measure the effects of different numbers of coil and the effects on current and magnetic field.

this is the measurements of the inductance and then magnetic field as the number of coils increases.

using these values we can calculate the elength of the wire. Science is a magical and disturbing beast.

11-13-2014 motors and magnetic fields

• The Hall Voltage is the potential created across a current-carrying metal-strip when the strip is placed in a magnetic field perpendicular to the current flow in the strip. (Actually, the magnetic field does not have to be totally perpendicular to the strip, the magnetic field only needs to have a component that is perpendicular.)
• When the majority of charge carriers are positive, they are deflected to the top of the strip so that the top of the strip attains a higher positive potential. If the majority of the charge carriers are negative then the top of the strip will become negative and the polarity of the Hall voltage will reverse. 

this is a saint louis style motor. it consists of a wire wrapped iron core on an axis spindle. the wire ends are connected to a split ring commutator. the split ring rotates between the fixed contacts as as shown.

11-4-2014 Magnetic fields and forces

This shows that no matter what, there is always two ends to a magnetic pole. They exist only in their relativity. if there is not a north pole then there is no south pole, but in a magnet they can never be removed or seperated.

This is metal fillings reacting to the magnetic field. showing that polarizing effects of the bar. mind blown.

just like electric fields, magnetic fields work in a similiar fashion.

electric fields have electric charge and electric flux.
magnetic fields have magnetic charge and magnetic flux
their relationship is circular.

this shows that the force created by a magnetic field and a current is a cross product. The force is therefor perpendicular and in the direction in accordance to the right hand rule, by pointing your hand in the direction of the magnetic field and then curling it in the direction of the drift velocity.

an example calculation, and an attempt to make an addition to the right hand rule, or possibly the left hand rule. no one knows anymore. this has become a dark place.

This shows that the magnetic field does not to any work on the already moving particles by creating the force. The cosine of phi is zero.

This is a microwave emitter, i dont remember why we got it out. oh wait i remember i think. it accelerates particles. by applying the magnetic field and the current, i think. anyways this thing is pretty awesome.

• Since the magnetic force always acts at right angles to the charges motion, the magnetic force can do no work on the charge. The B-field cannot speed up or slow down a moving charge; it can only change the direction in which the charge is moving.
• The general path of a moving charge in a constant magnetic field is that of a helix with its axis parallel to the direction of the magnetic field.
• If you stand in such a way that you are looking directly into the oncoming magnetic field, the a positively charged particle will be seen to rotate in clockwise circle where as a negatively charged particle will rotate in counterclockwise circle.

• The component of velocity of the charged particle that is parallel to the magnetic field is unaffected, i.e. the charge moves at a constant speed along the direction of the magnetic field.
• If the particle has a component of velocity parallel to the magnetic field, then its circlular motion will drift at a constant speed (equal to that of its parallel-velocity component, v_ll) along the magnetic field producing an overall helical motion. 

This video shows the effect of the currant and the magnetic field, and the cross product being the force in the upward position. 

If the current is changed or the magentic field is changed then the force is changed. Never cross the fields.

This is showing how a magnetic field going through a ring perpendicular would have no force on the system because it would cancel out, but if it is done at an angle, it could create a torque. which could be used to make a motor.

this chart shows the change in the force created by a magnetic field moving through a semi circle. At the zero and pi radians it is zero because the forces are either opposing each other or they are parallel. as well the sum of these is an approximation of the total force created by the current and the magnetic field.

10-30-2014 diodes and transistors

When the negative end of the circuit is hooked up to the N-type layer and the positive end is hooked up to P-type layer, electrons and holes start moving and the depletion zone disappears.

When the positive end of the circuit is hooked up to the N-type layer and the negative end is hooked up to the P-type layer, free electrons collect on one end of the diode and holes collect on the other. The depletion zone gets bigger.

A transistor is a semiconductor, meaning that sometimes it conducts electricity, and sometimes it doesn’t. Its internal resistance varies, depending on the power that you apply to its base. NPN and PNP transistors are bipolar semiconductors. They contain two slightly different variants of silicon, and conduct using both polarities of carriers—holes and electrons

The amplifier you just built was an analog amplifier.  The term “analog amplifier” refers to a circuit that can take an input voltage that can vary continuously over time and either boost the voltage or current to create a higher power output signal that also varies continuously over time.  Many ICs are digital rather than analog circuits.  Let’s explore the meaning of the term “digital.”

            Counting and displaying numerals, as in a digital watch, are operations that require a different type of electronic signal and circuitry than the continuously varying signal characteristic of audio electronics.  Digital electronics involves voltages that are either “on” or “off.”  The voltage is either zero (“off”) or at some other fixed voltage which is defined as “on.”  The 0 and 15 Volt digital circuitry you will be using will interpret any voltage greater than about 3 V as an “on” state and any voltage less than about 2 V as an “off” state.  One advantage of digital circuitry is that it is remarkably insensitive to stray variations or “noise.”  Thus, digital recorders, computers, and other modern digital devices are vastly more accurate and reliable than circuitry that attempts to reproduce varying signals.

When the base emitter junction is forward biased, a small current will flow into the base. Therefore holes are injected into the P type material. These holes attract electrons across the forward biased base/emitter junction to combine with the holes. However, because the emitter region is very heavily doped, many more electrons cross into the base region than are able to combine with holes. This means there is a large concentration of electrons in the base region and most of these electrons are swept straight through the very thin base, and into the base/collector depletion layer. Once here, they come under the influence of the strong electric field across the base/collector junction. This field is so strong due to the potential gradient in the collector material mentioned earlier, that the electrons are swept across the depletion layer and into the collector material, and so towards the collector terminal

This is a clean bread board. It has a bright future and infinite possibilities. Every hole is a new possible circuit that could lead to the next big thing. THE NEXT BIG THING.

electronics and oscilloscopesIntegrated Circuits, or ICs, are amazing devices in which tiny transistors (which you haven’t learned about yet), diodes, capacitors, and resistors are connected together with thin metal films to make elaborate circuits. The techniques for making ICs have improved so much in the past few years that we have advanced from having ICs to VLSIs (very large-scale integrated circuits). VLSIs have up to a million circuit elements in them and can do very complex things. When an IC is bundled together and put in a single package, it is often encased in black plastic that has two rows of connectors on it. Thus, an IC tends to look for all the world like a bug in the centipede or millipede family. You will be using several types of “bugs” in this unit.

Electronics is the sub-field of electricity that deals with the information contained in electrical signals, such as those that produce sound from a loudspeaker, a TV picture, or memory states in a computer.

            This unit is intended to provide you with a brief introduction to electronics, including some of the devices used in circuits and some of the ways you can transform electrical signals by designing and constructing circuits.  In the first part of this unit you will learn to use an oscilloscope, which is one of the most basic measuring instruments used in electronics to measure voltage changes.  Next you will explore analog electronics by constructing a simple amplifier to boost a weak electrical signal so that it becomes an audible sound when attached to a loudspeaker.  Then you will begin an exploration of some of the digital electronic components that provide the basis for the modern digital computer.  Finally you will use digital electronic components to build a stopwatch.  The projects in this unit might stimulate you to learn more about electronics on your own or to take a course in electronics.

This is an oscilloscope. It is an instrument who most usual application is to give a visual display of time varying voltages.

Integrated Circuits, or ICs, are amazing devices in which tiny transistors (which you haven’t learned about yet), diodes, capacitors, and resistors are connected together with thin metal films to make elaborate circuits.  The techniques for making ICs have improved so much in the past few years that we have advanced from having ICs to VLSIs (very large-scale integrated circuits).  VLSIs have up to a million circuit elements in them and can do very complex things.  When an IC is bundled together and put in a single package, it is often encased in black plastic that has two rows of connectors on it.  Thus, an IC tends to look for all the world like a bug in the centipede or millipede family.  You will be using several types of “bugs” in this unit.

This is a function generator using a speaker to generate sound with regards to an alternating currant.

By changing the frequency you can make the beat drop. Any physics 4B student, upon completing the class, is applicable to be a professional DJ and or hiphop musician artist, or what ever they are called.

These are subjectective observations from attaching the function generator to the speaker.

This oscilloscope is displaying a wave function such as sine or cosine.

this oscilloscope is displaying a square function. It is for squares.

When the x and y values are crossed, it can become a ring when the frequency and the period match up.

You will be given a mystery box with several terminals.  You need to make a diagram on your whiteboard showing what each of these terminals produces by making measurements with the oscilloscope.   Take a picture of this diagram for your Blog.