Sunday, February 23, 2014

Circuits


There are two different circuits we learned about this week in class. The first type is a series circuit. Basically this is a circuit that has only one path to take because the resistors are arranged in a chain like form. One characteristic of this circuit is that current is the same all the way through. Another thing that is special to this circuit is that the resistance can be found by simply just adding up all of the resistances.
An example of a series circuit includes a flashlight because the entire mechanism has only one circuit that makes it work. This is an image of my uncle's flashlight:
The switch, wires, and bulb are all together in one circuit making it a series circuit.

The second circuit that we learned about is a parallel circuit. In this type of circuit resistors are arranged with their heads together and their tails together. Unlike a series circuit a parallel circuit breaks up into different paths. One characteristic of this circuit is that voltage across the circuit remains the same. When calculating the resistance of a parallel circuit you must add all the resistor values in inverse then again inverse the answer. 










Sunday, February 16, 2014

Ohm's Law


This week in class we learned about Ohm's law and how important it is in physics and understanding circuits. Basically what it is, is an equation that can be used to understand and find certain variables for potential difference, current, and resistance.

These are Ohm's Laws:
(http://www.electronics-tutorials.ws/dccircuits/dcp23.gif)
The basic equation for all three equations is V=I*R and from that one equation you can derive two others that are used to help find variables in a circuit. The reason why these equations are known as Ohm's laws are due to the fact that Georg Ohm was the person who founded these equations and their function in physics. V stands for voltage, I stands for current, and R stands for resistance in a circuit.

Power is the rate at which energy is converted from the electrical energy of the moving charges to another form of some kind. We have seen power in previous parts of this course and it is relatively the same here. The amount of work being done basically. We can solve for power using this equation: P=VI. P stands for power, V stands for volts, and I stands for current. Another way to solve for power is using a variation of Ohm's law:
http://www.radioing.com/hamstart/ohms.gif
If you look at the blue section of this image, that is the equations that can be used to find power using Ohm's law.

It is obvious how useful Ohm's law in this unit. 

Sunday, February 9, 2014

Electricity

This is a picture of an outlet, this is where electricity is drawn from.
Typically a regular wall plug like this disperses 120 volts of electricity.

What is electricity?
According to the dictionary, electricity is a form of energy resulting from the exsistance of charged particles. Electricity can be measured in watts. Electricity is considered a secondary energy source because it is made of many primary sources.

Why is electricity important?
Electricity is very important today for many reasons. The first and most broad reason is because it powers almost everything that we humans use in everyday life. Electricity, so to speak, makes our world go round. It powers almost everything from a phone to an entire household. Electricity is important because humans have found a way to use it so that it may save lives. A heart defibrillator is an electric box that basically shocks your heart and can bring a person back to life. Electricity helps many of us live life. It powers our lights, TV's, phones, stoves, and many other things that are necessary in our lifestyles here in the 21st century. Without electricity the world would just not be the same.

What is electric current?
Electric current is the flow of electric charge. Typically electric current is a flow of electrons through a wire. There are different ways to calculate current in a circuit. The first way is to use the equation I=Q/T. I stands for current, Q stands for the charge, and T stands for the time. Another equation used to calculate current in a circuit would be a part of ohm's law which I will later talk about in a different post. Current is measured in amperes, or otherwise shortened and known as amps.

What is resistance?
Resistance is the delay of movement of a charge in a circuit. Resistance is directly related to the length of a wire in a circuit and the number of collisions. Resistance also has an inverse relationship to the cross sectional area of a wire, which is basically how thick that wire is. It makes sense the the more area electricity has to flow the lower the resistance. Resistance is measured in ohms, and to calculate resistance we use Ohm's law, V=IR. V stands for volts, I stands for current, and R stands for resistance. This equation is very useful in trying to find multiple values.

Tuesday, February 4, 2014

Capacitors

Capacitor is something that holds energy in an electric field between two plates. Capacitors are very common in our world. Capacitors can be found in many various electronics. Such as TVʻs, DVD Players, and even computers. Capacitors are very important in our lives because they are what powers many of the things used in our everyday lives. Another example of a capacitor in our everyday lives is in a defibrillator. A defibrillator is used to start people's hearts if for some reason they stop beating. Obviously capacitors are very important in everyday life and they are useful. The science behind this concept is pretty straight forward. There is an electric field between two charged plates. The picture above is a picture of flash. Flash is also considered a capacitor.