Electric Motor DAY~

Our Recipe For Fail To Work Electric Motors!!

Ingredients:  One Piece of Wood                     Thumb Tacks
                    Four 4-inch Nails                         Commutator Pin (Smaller Nails)
                    Axel Stick                                    Wire
                    Paper Clips                                  Cork
                    Pop Can                                      Magnet


Cooking Instructions:

Begin by hammering 4 nails onto the piece of wood, in a 6cm by 3 cm rectangle fashion.
Then put the Axle Stick in the center of the cork.
Put the two commutator pins beside the axle on one side of the cork.
Murder two paper clips and turn them into hoops.
Tape the hoops down parallel to the symmetry length line of the rectangle.
Coil the wire in the same direction with the full length of the wire around the cork and two commutator pins.
Insert the axle into the hoops and test spin.
Then cut the pop can into two small pieces of rectangles, these will be your brushes.
Sand both sides with sandpaper until your hand turns gray.
Place the two brushes so that one side is touching a commutator pin. Keep them in place with thumb tacks.
Mount the magnets onto the nails.
Add a dash of electricity through the brushes.
Watch the motor spin and go sparky sparky.


This is the results of our hard work. It ended up not spinning and going sparky sparky. We had a lot of recommendations from our fellow classmates, some being; the wire is not coiled properly, the brushes not being sanded enough, and the brushes and nails are too close to each other.


We will try all these ideas and hope that our motor will work tomorrow.
 Never Give Up, Fight!

Magnetism and Electromagnetism

17.1 The Magnetic Force - Another Force at a Distance

Magnetic field: Is the region where the magnetic force of a magnet is distrbuted.
This pictures shows the magnetic field of magnet with iron powder, as you can see the field in around the north and south side of the magnet.

If two magnets are facing each other on the opposite pole they would attract. Meaning that if north and south pole were facing each other they would attract like in the picture. But if the same poles would face each other, they would repel.

Magnetic forces don't just work on magnets, they also work on different metals. These metals are called ferromagnetic metals.
Domain Theory: This theory stats that all large magnets are made up of smaller and rotatable magnets, dipoles, which interact with each other. If these dipoles a line, then a magnetic domain is formed.

Electromagnets
Oersted's Principle: Oersted discovered that charges moving through a conductor produces a circular magnetic field around the conductor.
By knowing this information, we have been able to developed several hand signs to help predict how magnetic forces act.

Right Hand Rule
 First right hand rule for conductors: This rule can be used to find the direction of the current or the direction of the magnetic field if one of the factors are given. For example, if the current was moving left, then the magnetic field would be clock-wise.

As shown in the picture, the thumb would point in the direction of current flow while the curl of the figures would show the magnetic field.








Right Hand Rule # 2
This rule can be applied to a coiled wire conductor. This is done to strengthen the magnetic field by coiling the wire in a linear cylinder. This second right hand rule is to find the conventional current flow and the north side of the field.

For example, if the finger curls point in the direction of the current, inward, then the north side of the field is left. This north side of the field is represented by the direction the thumb is pointing.

16.5 Current Electricity and Electric Circuits

16.5 Resistance Ohm's Law
George Ohm was a German physicist that experimented with electric currents, the results of his research helped us understand the relationship between current, resistance and voltage.
Ohm found that the potential difference ( V ) in volts divided by the current ( I ) in amperes was constant with the resistance in a circuit.

Example Question
 An electric stove is connected to a 200 V supply and has a known resistance of 15 Ohms. What current will this element draw?
Given:
V = 200 v     R = 15 Ohms   I = ?       

V = IR      therefore  I = V / R                   

I = 200 V / 15 Ohms              
  =  13.34 A
Therefore, the current that the element will draw is 12.34 A.

Factors of Resistance
There are many things that effect the resistance of a circuit, such as the length and thickness of a wire, the temperature, and the material it is made of.

Table 16.4 Factors that affect resistance

Length                 The longer the conductor is, the greater the resistance will be.

Thickness            The thicker the conductor is, the lesser the resistance will be.

Material               Some materials such as copper, is better conductors then others. Resistance of a substance
                            is call resistivity.

Temperature        The higher the temperature is, the resistance tends to also increase and Vice Versa.

Prelab : Table of Terminology

Name	Symbol	Unit	Definition
Voltage	V	Volt	Voltage is the electric potential difference, which is the energy required in joules over the charge in coulombs.
Current	I	Amperes	Current is the distance traveled in a circuit, over the amount of time for it to reach that distance.
Resistance	R	Ohm	Resistance is the potential difference in volts over the current in amperes.
Power	P	Watt	Power is the amount of work performed.

Series and Parallel Circuits

Series Circuit
A series circuit is a circuit with only one path for the current to flow, this path has multiple resistors which receives the different amount of voltage.

This picture shows a series circuit with 3 light bulbs (resistors) and a power source (battery), all connected with a single path of current flow. Since all three light bulbs are in the same circuit, the amount of energy received from each bulb is lower then the once before. If one of the bulbs were to burn out, then the whole circuit would stop working. 




Parallel Circuit
A parallel circuit is a circuit with loads that are parallel with each other. Unlike the series circuit, the parallel circuit has more then one path for the current to flow but each load has the same amount of voltage.

This picture shows a parallel circuit with 3 resistors next to each other. Since each resistor is in its own circuit, if one resistor were to stop working, it will not affect the other resistors.

Energy Ball Questions

On Friday, we were put in groups and were given 1 ping pong ball and 12 questions to answer.

The ping pong ball turned out to be a simple circuit which would light up if we used our fingers to complete the flow of current.

Smiley Question 1) Can you make the energy ball work?

            Answer:      Yes, we all tried it and it began to hum and flash.

Smiley Question 2) Why do you have to touch both metal contacts to make the ball work?

            Answer:      Both metal contacts needed to be touched for the ball to work because you are completing the circuit, if you are not touching both pieces then the energy will not circulate.

Smiley Question 3) Will the ball light up if you connect the contacts with any material?
            Answer:      No, the ball would only light up if you are using materials that conducts electricity. So, materials like paper and clothes will not light up the ball.

Smiley Question 4) Which materials will make the energy ball work?
            Answer:      Out of all the different materials we tried, the ones that worked were; skin and a metal spoon.

Smiley Question 5) This ball does not work on certain individuals, what could cause this to happen?
            Answer:      The ball worked on everyone in the class, but an educated guess would be that that individual is dehydrated or too bony. Humans conduct electricity because they are 70% water, so it is possible that the ball would not work on a dehydrated person. Also, a fellow classmate tried to put his knuckles on the contacts, causing the ball to turn off and on. 

Smiley Question 6) Can you make the energy ball work with all 5-6 individuals in your group?
            Answer:      Yes, the energy ball worked when we linked our pinkies together and formed a longer path for the flow of energy.

Smiley Question 7) What kind of circuit can you form with one energy ball?
           Answer:       The circuit we formed as a group was a simple circuit.

Smiley Question 8) Can you make it work with 2 balls?
           Answer:      Yes, when we tried it with 2 balls the results were the same. I'm guessing that as long as the circuit is connected properly the 2 balls should light up.

 Smiley Question 9) What do you think will happen if one person lets go of the other person's hand and why?
            Answer:        I think the ball would stop working because if one person lets go of his or her hand, the flow of current would stop at the hand and the circuit would be incomplete or "switched off". When we tested this out with our group the results were true to our hypothesis.

 Smiley Question 10) Does it matter who lets go? Try it.
              Answer:        No, the ball will stop working if anyone in the human circuit were to let go of their hand.

Smiley Question 11) Can you create a circuit of two energy balls where only one lights up?
               Answer:       Yes, it is possible to create a circuit like this. The answer is the parallel circuit, because the flow of current only goes one way, a switch can be added to stop one ball from lighting up while other ball it still in a fully working circuit.

Smiley Question 12) What is the minimum amount of people needed to complete this?
               Answer:       
If each line represents a person, then the minimum amount of people needed for this circuit is 5 people.

Blog 1: Notes on Current Electricity

This device is used to measure the amount of electric current that runs through a circuit. The currents are measured in Amperes, so this device is called an Ammeter.

 A current is the flow of electric charges that passes through a conductor. Current can be measured by the formula:


I, represents the amount of current, measured in amperes. Q, represents the distance travels through the conductor. t, represents the time it took for the current to pass this distance in seconds. 

Example  
How much current flows through a hair dryer if 1400 C of charge pass through it in 3 minutes?

Given
Q = 1400C  t = 3 min  I = ?

Solution
t = 3 min (60 s / 1 min) = 180 s

I =  Q / t
  =  1400 C / 180 s
  =   7.78 C/s

Voltage is the electric potential difference which is represented by the formula:
V = E / Q
Where E represents the energy needed in joules and Q represents the charge in coulombs.

Voltage is measured by a voltmeter, which compares the potential difference before and after the load.