Circuits
There are two types of circuits that we dealt with in this lab. One type is a RC circuit, which has a power supply, resistor and a capacitor. The other type is a LR circuit, which has a power supply, inductor and a resistor.
The first one was a RC circuit. The capacitance (C) of a capacitor is equal to the charge (Q) on either plate divided by the potential difference (VC) between the plates.
C º Q / VC
The capacitance has the units of farads (F). Using Kirchoff's Loop Rule, we know that The voltage drop across the resistor (VR) plus the voltage drop across the capacitor (VC) equals the voltage rise across the battery (x). This equation looks like:
VR + VC = x
Using Ohm's law and the definition of current we get:
VR = IR I = DQ / Dt
Therefore: VR = (DQ / Dt )R
Using the above information, we can rewrite Kirchoff's Loop Rule, which looks like: R(DQ / Dt) + (Q / C) = x
Substituting the following variables x and t, we can look at the equation a different way. Here are the definitions of these variables:
x º Q - xC t º RC
To get the charge as a function of time, we use this equation
Dx / Dt = - x / t
By graphing x versus time, we get the following equation:
x = x0 e(-t / t)
x0 is the value of x at t = 0. If we replace the x in the above equation with the definition of x, we get:
Q = Q¥ (1 - e(-t / t))
Substituting the above equation into the equation for capacitance and resistance, we get: VC = x(1 - e(-t / t)) VR = xe(-t / t)
Since current (I) is VR / R, we can get the equation:
I = I0e(-t / t)
Discharging a capacitor in a RC circuit can be related to time also. This is seen in the following equation:
DQ / Dt = - Q / t
Relating this equation to a similar equation that we defined earlier, we can get:
Q = Q0e(-t / t)
Using the definition of capacitance and Kirchoff's Loop Rule, we can expand the above equation to these equations:
VC = xe(-t / t) VR = -xe(-t / t)
Using the definition of current, we get:
I = -I0e(-t / t)
The other type of circuit was a LR circuit. The back emf (xL) is equal to the rate of change of the current times the inductance of the coil (L).
When explaining the topic, I was completely lost and had trouble catching up but as soon as there was a demonstration, I soon caught on and was able to complete each equation with confidence.
In recent years there has been a growing trend involving the use of closed circuit
From these last two equations, we can make a third equation involving all of the variables.
When the applied signal is a sinusoidal voltage wave and the resulting signal is a sinusoidal current wave, then X is called the impedance Z; conversely, when the applied signal is a sinusoidal current wave, the resulting signal is a sinusoidal voltage wave, X which is called the admittance Y.
B. A coil is connected to a galvanometer, completing the loop. Many magnets are passed through the coil.
This expression is the rate law for the general reaction above, where k is the rate constant. Multiplying the units of k by the concentration factors raised to the appropriate powers give the rate in units of concentration/time.
Medicine and electronics are rapidly becoming a common partnership. Electronics and medicine has been around for over a hundred years. This application can be seen in early X-ray machines, as well as early doctors and healers who felt that electricity possessed something special that assisted the healing process of many illnesses and injuries. But it has not been the last forty to fifty years that the development and refinement of electricity as medical agent has occurred. Today the medical field can not imagine itself without the assistance of electricity and electronic components.
A battery is a device which converts chemical energy into electrical energy. A battery usually consists of two or more cells connected in series or parallel, you can also have a single cell battery. All cells consist of a positive electrode, and a negative electrode. An electrolyte is a liquid substance capable of conducting electricity. In this substance one of the electrodes will react producing electrons, while the other will except electrons. When the electrodes are connected to a device to be powered, called a load, an electrical current flows.
The pulsed charger provide the current to battery in pulses. The rate of charging is controlled by the width of pulses about one second. During the process of charging milli second’s periods allow the chemical reaction to stabilize and due to this no gas is produced and safe charging is happen.
To demonstrate the use of calculus, we will be taking certain examples and solving them
AC and DC literally stand for Alternating Current and Direct Current. Direct Current is very convenient and is used in many modern day utilities. For a circuit with DC the current is constanly in one direction, while the voltage remains constant. This makes for a simplistic circuit, for example a flashlight, The batteries are a source of electrochemical DC power and . However AC is called Alternating Current because the voltage changes from negative to positive a given number of times a second, this is also described as the frequency of the power. An example of this would be a motor ran by a hand crank. The inversing of charges creates a sinusoidal graph which looks something like figure 1 (given in radians). This makes for an unsteady power source and can often times be warped from the sinusoidal shape. So the main difference between AC and DC is the way the energy is transmitted.
Faraday continued his electrical experiments. In 1832, he proved that the electricity induced from a magnet, voltaic electricity produced by a battery, and static electricity was all the same. He also did significant work in electrochemistry, stating the First and Second Laws of Electrolysis. This laid the basis for electrochemistry, another great modern industry.
-What is the difference between method and device? A method is a device which you use twice.
charged. A capacitor can then be used in a circuit on its own with out