Right Hand Rule #1 & #2

Right hand rule #1 (conductors):

Thumb of right hand points in direction of conventional current flow, fingers point in direction of circular magnetic field around conductor.

Right hand rule #2 (coil):

Curled fingers of right hand point in direction of conventional current flow, thumb points in direction of magnetic field around conductor.

Concept Map + Ten Things Must Know

In physics class today, we did something called CONCEPT MAP on electricity unit. It is helpful to visual learners because all the parts of the units are grouped with relations to one another. However, I personally find the concept very confusing and not easy to follow along, and I would study better in other ways.

Anyways. here are some photos taken in class today:

Our own map and other groups' :D

10 Things WE MUST KNOW :

1) Current : rate of flow measured in coulombs per second (amperes) by an ammeter connected in series.

2) Electric Charge: measured in coulombs where 1C =6.24 X 10^ 18 electrons.

1 electron has a charge of 1.60 X 10^-19 C.

3) Series Circuit: charge flows along one path .

4) Parallel Circuit: charge flows along two or more paths.

5) Ohm's law: R=V/I V=IR I =V/R

6) Conventional Current/ Electron Flow: flow of charge from positive terminal to negative terminal for conventional, and from negative to positive for e- flow.

7) Kirchhoff's Law:

For Series:

Current:

It = I1 = I2 = I 3...=In

Potential Difference:

Vt = V1 + V2 + V 3...+Vn

Resistance:

Rt =R1 + R2 + R 3...+Rn

For Parallel Circuit:

Current:

It = I1 +I2 + I 3...+In

Potential Difference:

Vt = V1 =V2 =V 3...=Vn

Resistance:

1/Rt =1/R1 + 1/R2 + 1/R 3...+1/Rn

8) Power : rate at which work is done. P=VI or P= E/t

9) Energy: work, in Joules. E= Pt, E=VQ or E =VIt

10) Potential difference = voltage drop across two given points in a circuit. V=P/I. Measures by voltmeter which is connected in parallel.

Ohm Vs. Kirchhoff's Law !!

As learned in class, the Ohm law says that the current that goes through a conductor between two give points is directly proportional to the potential difference or the voltage. The current is inversely proportional to the resistance. Given the triangle :

We can figure out from this triangle relationship of ohm's law that :

V= IR

I = V/R

R= V/I

Kirchhoff's Law is based on two equalities that deal with the conservation of charge and energy in the circuits.

For Series Circuit:

Current:

It = I1 = I2 = I 3...=In

Potential Difference:

Vt = V1 + V2 + V 3...+Vn

Resistance:

Rt =R1 + R2 + R 3...+Rn

For Parallel Circuit:

Current:

It = I1 +I2 + I 3...+In

Potential Difference:

Vt = V1 =V2 =V 3...=Vn

Resistance:

1/Rt =1/R1 + 1/R2 + 1/R 3...+1/Rn

Top Roller Coasters!

I've found some really interesting roller coasters on the website recently, and I would really like to share the pictures.

1. Voyage, Holiday World

Roller coaster enthusiasts from all over the WORLD voted the Voyage the number one wooden roller coaster on the planet for four consecutive years.

Features:

Most dramatic drops on The Voyage measure 154 feet (66-degree angle of descent), 107 feet (51-degree angle), and 100 feet (50.5-degree angle).

2. El Toro, Six Flags Great Adventure

El Toro features the steepest drop of any wooden roller coaster in the country at a record-breaking 76 degrees. It combines all the best features of wooden coasters with the smooth speed of their steel counterparts. One can experience the weightlessness with nine separate airtime chances.

3. Bizarro, Six Flags New England

The best steel coaster for the fifth time. It takes into another dimension with fog and fiery flame effects timed JUST perfectly with heart-pumping audio for an incredible ride.

The Battery Circuit !!! Electron Flow Vs. Conventional

In Physics class today, we discussed about two things that seem like the exact same things, but in fact they are the direct opposite-conventional current flow and electron flow.

Electron flow is simply the movement of electrons through a circuit, and conventional current is the movement of the positive charge. As you can see from the following diagram of a battery circuit, it has a battery (cell), an open switch, a load (light bulb) and the arrows showing the directions of the movements. In conventional current flow, it is said to be that the electricity moves from the positive electrode of the cell through the circuit to the negative end ( +----> -).

For electron flow, the electrons are moving from the negative end through the circuit to the positive side (- -----> +).

The Energy Ball Experience

On Friday, we had our first official physics class with Mr. Chung. The reason that I looked forward to this class was because the teacher is humorous and we could play around with different and interesting "toys" instead of doing textbook work.

We got to play around with very "expensive" pingpong balls that he called the Energy Balls. The energy ball was made of a circuit board with a light bulb that could flash and a buzzer that could make noises. The circuit board was connected to two metal pieces by different wires, and in order for the light bulb and the buzzer to work, both metals had to be touched by conductors like our fingers. When the metals were touched by two different people each with one finger and without them touching each other, the energy ball did not work. This was because it was not a complete series circuit.

When the whole class was given the task to make one ball light up and the other one off while touching one another, the class formed another type of circuit called the parallel circuit. This time there were two resistors, and the electricity had several paths that it could travel. Instead of forming a circle like the series circuit, there was a "line" that cut the circle in half. There were two switches, one on each end. If one end "disconnected", that relevant energy ball would not light up while the one on the other side would still work.

The major difference between a series circuit and a parallel circuit is the way the components (in this case the energy balls and our hands) are connected. In a series circuit, there is only one path for the flow of electricity. For example, Christmas tree lights, if one part of the path is damaged, the rest of the light would not function. In a parallel circuit, there are more than one path of current flow, and if one part of the circuit is obstructed, the current can find other paths.

Series Circuit:

Parallel Circuit:

The energy ball does not work on certain individuals is probably due to the calluses on the palms of their hands. The calluses most likely resists the flow of electricity, therefore when in touch with the metal pieces, the calluses act like insulators which prevents the energy ball from lighting up.