Right Hand Rules #1 & 2

-Right-hand rule #1 (conductors)-

First make sure that your thumb of your right hand points in direction of conventional current flow, then make sure your fingers are pointed in the direction of circular magnetic field around conductor.



-Right-hand rule #2 (for the coil)-

First make sure that your curled fingers of your right hand points in the direction of conventional current flow, then your thumb has to point in the direction of the magnetic field around conductor.

P. 582-589 notes

The magnetic force

-Magnetic field is the distribution of a magnetic force in the region of a magnet.

-Magnets also attract Ferromagnetic Magnets which are iron, nickel and cobalt.

-Demagnetization is when the Ferromagnetic materials lose their magnetic strength.

-Reverse magnetization is the polarity of magnets reversed.

-Breaking of a large magnet is breaking large magnets into smaller magnets.

-Maximum strength is a magnet which can only become so strong and no more.

-The Domain theory of magnet states that large magnets are composed of smaller magnets which are rotatable. Rotatable magnets are known as Dipoles.
-domains that are pointing in random directions can be alligned if they are placed in a large field with a fixed direction.
-domains could lose their order and point in different directions, causing a dilution and overall weakening of the magnet.
-Large magnetic fields pointing in the opposite direction cause all the domains to line up with the new field, reversing the overall magnetic polarity.
-In all the pieces, the domains still line up, so each acts like its own magnet.
-Once all the domains are aligned, there is no way to increase the magnet's strength any further.

- Normal magnets can never be shut off. However, scientists created the Electrical Magnet which can be shut off at will.

-Oersted Principal- Charge moving through a conductor produces a circular magnetic field around the conductor.

-The Right hand rule are several hand signs to help you predict how magnetic forces act.

-The 2 right hand rules:

Conventional flow #1- use your right hand pointing in the direction of conventional or positive (+) and the curved fingers point in the direction of the magnetic field around the conductor. This shows how it can predict the direction of the magnetic field around a straight conductor.


Conventional flow #2- use your right hand with curved fingers pointing in the direction of conventional or positive (+), current flow. the thumb points in direction of the magnetic field within the coil. Outside the coil, the thumb represents the north (N) end of the electromagnet produced by the coil. This predicts the relationship between the direction of conventional current flow in a coil and the direction of the magnetic field at the end of the electromagnet.

Chpt 16 notes. page- 553-563

The amount of energy transferred to any useful device depends on two things:

-The potential different of the power supply (the amount of push).

-The nature of the pathway through the loads that are using the electric potential energy.

Volt & conductivity can determine the amount of current flow.

Equation for Ohm's law: R(Ω) = V(V)/I(A) 

 

R: Resistance, measured in ohm (Ω)- is the opposition of flow and can make the pathway in a circuit more difficult to flow.

 

V: Voltage, measured in volt (V)- determines the amount of current flow.

 

I: Current, measured in amperes (A)-  is a flow of electricity through a conductor.

Superconductivity: Ability of a conductor conducting electricity without heat loss due to resistance. The highest temperature it can reach is (-133°C)

 

Factors which affect Resistance can be Length- by how long it is, it affects how great the resistance is. Cross-sectional area- by how thick or large it is, there will be less resistance. Materials used- not everything are conductors, so what is used can affect it. Lastly, Temperature- as you may be aware of, matter separate once it is heated up, so higher temperature increases resistance.

 

Kirchhoff’s current law: The total amount o f current into a junction point of a circuit equals the toal current that flows out of that same junction

 

 

 Kirchhoff’s voltage law: The total of all electrical potential decreases in any complete circuit loop is equal to any potential increases in that circuit loop.

 

Kirchhoff’s law: 

 

Ohm’s law: R=V/I,

Chart

 

Name

Symbol

Unit

Definition

Voltage	V	Volt(V)	The electrical potential energy for each coulomb of charge in a circuit.
Current	I	A	A flow of electricity through a conductor.
Resistance	R	Ohms(Ω)	A measure of the opposition to current flow.
Power	E	Watt(W)	The rate of which work is done. ©Tomeo®

Difference between a series circuit and a parallel circuit.

Series Circuit:

A series circuit is a circuit that only goes in one direction without any resistors going through the middle. However, if any resistor goes out, then everything will not work.

A series circuit is a closed circuit and it is joined, so every individual resistor would get their power faster.









Parallel Circuit:

A parallel circuit is when all the resistors are in separate rows. it is good because if one resistor is burnt out, the other resistors are still functioning.

A parallel circuit is not joined so it would take longer to reach every individual resistor. A parallel circuit is also a closed circuit.

Energy Ball Questions

Q1a. Can you make the energy ball work?
Yes, we can make the ball work by placing our fingers on the metal plates

Q1b. What makes the ball flash and hum?
Since there is a hole in between the two metal plates, we each need two fingers that is connected to connect the circuit.

Q2. Why do you have to touch both metals contacts to make the ball work?
Our fingers which acts as conductors to allow the electrons to run through our body to connect the circuit.

Q3. Will the ball light up if you connect the contacts with any materials?
No, not every object act as a conductor.



Q4. Which materials will make the energy ball work? Test your hypothesis
Certain objects which act as conductors. For instance, salt water and metal.

Q5. This ball does not work on certain individual what could cause this to happen?
That event occurs when only one side of the metal plate has been touched. Or if you are nor charged enough, because of contact with positive or negative charges. And you need to keep giving electrons to it from stealing electrons from others.

Q6. Can you make the energy ball work with all 5 ~ 6 individuals in your group? Will it work with the entire class? It does work, the currents just connect through all of us. It will work with the entire class as long as we are all connected.

Q7. What kind of a circuit can you form with one ball?
A series circuit, because it only goes in one direction.

Q8. Given 2 balls (combine 2 groups): Can you create a circuit where both balls light up? [1/3]
Yes, we can create a circuit.

Q9. What do you think will happen if one person lets go of another person's hand and why? [2/3]
It does not connect so the circuit is opened.

Q10. Does it matter who lets go? Try it. [3/3] No, if one of us lets go, it doesn't work.

Q11. Can you create a circuit where only one ball lights (both balls must be included in the circuit)? [1/2]
Yes, using a parallel circuit.

Q12. What is the minimum number of people required to complete this? [2/2]
At least one person.

challenge!

The physics of tall structures:

A tall structure must have a stable and strong base. The reason to that is because the base must always be heavier than the top. Since gravity is 9.8 m/s, the heavier the top is, the easier it is for the structure to collapse. Known from the equation-

And also:

We can understand how to calculate the structure stability from gravity. But also there are other factors such as the wind, that can not be calculated... but we can understand how stable a tall structure is using the wind. You must first understand that the wind can be quite strong, so it can blow down a structure if it is weak. We can prevent that from happening may be to make all the parts tight together. We can also calculate the potential energy of a tall structure by using the formula- Eg= mgh... but that is off topic.

What makes a tall structure stable?-

Tall structures have the disadvantage of being too unstable due to gravity (as shown above) but one thing which supports it greatly is the base. A strong base can contribute to many tall structures. For example, the CN Tower,  it becomes more narrow as it extends to the top. That makes it stable and tall.

What is the center of gravity?

The center of gravity is usually the point where the structure balances. That point would be the central point of a structure, even though it's called the center of gravity, it doesn't necessary have to be in the middle. The center of gravity can be slightly below the exactly middle of the building. The reason to that is because the base is much wider than the narrow part, so the center of gravity must be where two parts of a structure has the same weight. In that case where the base is the widest in the structure; the center of gravity is lower than the exact middle of the structure.

page 544-522 notes

1. I is the symbol for current and it is measured in A(ampere).
Q is the total amount of charge moving past a point in a conductor and is measured in coulombs(C).
t is the time taken to complete the process.

2. Q=Ne or N=Q/e
Q is the charge moving past a point in a conductor.
N is the number of electrons passed through Q.
e is the charge of one electron.

3. An ammeter measures the currents and it must be wired to all devices to be functional for current to flow through it.


4. Conventional current is the positive charge.

5. Direct currents flow in a single direction until it reaches it's destination.

6. The destination which consumes the energy from the Direct currents is called a load.

7. The alternating current is a current going in the direction reversed to which way it should flow to by using electrical or magnetic forces.

8. A circuit is the path of a current which helps the current flow from it's negative to it's positive side.

9. The electrical potential difference is symbolised as V using the equation:

V= E/Q

Q is the electrical potential of a charge.
E is the energy required to increase Q.
V is the potential difference.

10. Since V= E/Q , I= Q/T

E= VQ, Q=It









therefore E=VQ
                 =VIT
11. VIT is used to calculate the amount of joules of energy used.