Maria | Manga ch. 3

1.  When food is digested, heat is produced. So when electricity flows through an electrical resistance, heat is also produced.

2.  Because of thermal emission, as temperature rises the lightbulb becomes brighter.

3.  A superconductor is a material that can conduct electricity with zero resistance below a certain temperature. They can be used as superconducting electromagnets, such as in maglev trains.  Metals can become superconductors at low temperatures.

4.  Ampere's Law states that for any closed loop path, the sum of the length element times the magnetic field in the direction of the length element is equal to the permeability times the electric current enclosed in the loop.

5.  The magnetic fields generated in each wire are combined to generate a magnetic field of twice the current around both conductors. A force of attraction is also generated between the two wires.

6.  A force of repulsion is generated between the wires. The magnetic fields negate each other and become smaller.

Manga 3

What is the relationship between heat and electricity. Please provide a metaphor.

When the electricity flows through a resistance heat is generated. A metaphor is like when you are driving it’s like the electric flow, traffic is the resistance, and heat is when your able to drive progressively (and get to class on time).

Why is it warm near an incandescent light bulb?

It’s warm because of the Thermal Emission. The thermal energy is emitted because the temperature of substance increases.

What is a superconductor? What are they used for in real life? You may have to look this up. How could one make a metal a superconductor?

Superconductors are materials that conduct electricity with zero resistance below a certain temperature. Mercury was historically the first to show superconductivity. “Magnetic-levitation is an application where superconductors perform extremely well. Transport vehicles such as trains can be made to "float" on strong superconducting magnets, virtually eliminating friction between the train and its tracks.” You lower the pressure and cool a metal to make a superconductor.

http://www.superconductors.org/uses.htm

What is Ampere's Law?

When the current flow goes through the electrical wire magnetic fields are generated and create a circular pattern. This is Ampere's Law.

If current of the same size flows in the same direction in two electric wires placed side by side, what happens?

They will be attracted to one another.

What happens if current of the same size flows in opposite directions in two electric wires placed side by side?

They will resist one another.

Please read about Flemings Left and Right Hand Rule. Think about this Rule with respect to the motors we have made this week.

It how the direction of flow is controlled. The left hand rule is in charge of direction of the current, the DC motors left hand force is in charge of the way the motor turns.