What I've Learned in IS3 During the Past 2 Weeks!

During the past two weeks, I have been studying electricity and magnetism in IS3. We have learned through various methods, starting with hands-on experiments and then going back to analyze what happened and why.
We started by making an electromagnet in class. To make our electromagnet, we wrapped copper wire around a nail and connected both ends of the wire to either side of a battery, this created a magnetic field around the nail and turned it into a temporary magnets (we tested this by attracting paperclips to the nail). We later learned that this happened because the flow of electrons around the iron nail (ferromagnetic material) creates a magnetic field. And, to strengthen the field, we coil the wire around the nail, creating a

After this, our next significant event was when we brought in our various different models of electric motors. This was mine:

We later found out how the motor works:

Motors turn electric energy into mechanical energy. Motors are normally composed of the following parts:

Armature: The armature is composed of two parts which have currents flowing in opposite directions (this is essential in the motor's function). It is attached to the commutator and continuously rotates.

Commutator (split rings): A commutator reverses the direction of the current every half turn.

Battery/ Energy source: The battery provides the current.

Permanent Magnet: The permanent magnet interacts with the magnetic field of the current flowing through the armature to cause the rotation (the fields constantly try to align themselves with one another however the current is being reversed, causing continuous motion).

Brushes: The brushes transmit the current to the commutator. They are not fixed on the commutator, rather they only lightly touch it.

As we know, an electric current has a magnetic field. Magnetism is essential in motors. As the current travels throughout the armature, the magnetic field around it becomes stronger and is attracted to the permanent magnet on the other side. This causes the armature to do a half-rotation. Once it has rotated half a time, the commutator is touching the opposite brush which causes the field to reverse and the armature to be attracted to the opposite permanent magnet. This is a cycle which will continue as long as there is a current and is what causes the motor to function and continue rotating. We use motors every day in automobiles, printers, computers, etc.

These eight goals guided our progress for the these last few weeks:

EM1: I can explain how electric charges interact.
Positive and negative charges attract and like charges repel each other. When charges bump into each other, resistance is provoked and heat builds up.




EM2: I can give examples of how charges can be transferred between materials and explain them.
Conduction, induction and friction are the three ways in which charges can be transfered between materials.


Conduction occurs directly between materials. The electrons flow through the material(s). Conduction requires a voltage source. Conduction is happening frequently; electrons moving from a copper wire to a lightbulb is conduction. Materials can be good or bad conductors depending on how easily electrons move through them; copper, for example, is a very good conductor, while ceramic or plastic are lousy ones.

Induction is the transfer of charges with no physical contact between the two materials. When a material has an unbalanced amount of charges and comes close to a material with balanced charges or opposite charges, the electrons will come together and produce electric discharge between them in order to balance out the charges. One example of when this happens is when you are about to touch something such as a doorknob and you receive a small "shock", this shock is the electric discharge.



Friction is the transfer of charges between materials who are rubbing against each other. Some materials, such as cotton or linen, are very easy to steal electrons from. Because of this, when one material rubs up against one of these materials, it will steal it's electrons and become negatively charged. One well-known example charges being transfered by friction is when you rub your socks agains a carpet in order to shock something. Your socks are stealing the electrons from the carpet and become negatively charged.

EM3: I can explain how an electric current is produced.
An electric current is produced from voltage. Voltage is a difference in potential energy; it provides a "push" towards the electrons which creates a current.

EM4: I can compare conductors with insulators.
Materials are mainly either conductors or insulators. Materials such as copper or iron are conductors because charges can flow easily through them. Materials such as plastic or ceramic make for good insulators because it is very difficult for charges to flow through them.

EM5: I can explain how resistance affects current.
Resistance is the difficulty for charges to pass through a material, for this reason, if there is greater resistance, current is reduced and vise versa. To decrease resistance and allow for greater current, you can: increase the width of your conductor or change the type of material you are using.

EM6: I can use Ohm’s law to calculate resistance, current or voltage.


Ohm's law involves a simple formula: RESISTANCE= VOLTAGE/ CURRENT. Using this formula, we can also find voltage or current as well.

EM7: I can build series and parallel circuits and describe its parts. 

We are now learning about circuits, their parts, and what affects them.

Circuits normally are composed primarily of an energy source (ex: battery), conductor(s) (ex: copper wire) and resistors (i.e. lightbulbs).

There are two types of circuits; series and parallel.

A series circuit has only one path for the electric current to take. This means that the electrons must pass through all of the resistors on the circuit, causing there to be more resistance (lightbulbs, for example, would be duller on this circuit because they have less energy). Apart from this, if one resistor is disconnected from the circuit, none of the others will get energy because each resistor is necessary for the electric current to continue.

A parallel circuit has multiple paths for an electric current to go through. This means there will be less resistance, as the current does not need to pass through every resistor. Also, unlike the series circuits, even if a resistor is disconnected, the others still have the ability to continue working because the electric current does not rely on each resistor to continue its flow. We found parallel circuits to be much more efficient than series circuits because they have less resistance and multiple paths for an electric current to flow through.

EM8: I can explain the relationship between power, voltage and current.

The energy source provides the "push" or voltage (also known as the difference in potential energy between two points in a system). This is what causes there to be an electric current (flow of electrons). The current flows through the conductor and is affected by the conductor's width/ length, heat and the material of the conductor. 

Resistance is the difficulty for the electrons to pass through the current. Resistance can be helpful in some situations (such as a shower) because it causes electrons to collide frequently which produces heat.

Resistance can be calculated using Ohm's Law: Resistance= Voltage/ Current.

*A washing machine using 220v that has a current of 10 amps, has a resistance of 22 ohms.

Power is the product of voltage and current and is the rate at which electrical energy is transformed.

*A washing machine using 220v that has a current of 10 amps, has a power of 2,200 watts.

Self-EvaluationAfter completing the unit, I now feel confident in understanding the various topics we covered in class as well as explaining them to my peers.





Pictures- http://www.ycars.org/EFRA/Module%20A/DCSeri6.gifhttp://www.physics247.com/physics-tutorial/images/parallelcircuit.jpghttp://www.themagnetguide.com/gifs/electromagnet.gifhttp://www.reuk.co.uk/Ohms-Law.html
http://www.howequipmentworks.com/physics/electricity/basic_electricity/basic_electricity.html