Question 1:
What is the relationship between heat and electricity. Please provide a metaphor.
First of all, a calorie is a measurement of heat. When this heat is flowing through electricity it is measured in joules, as in "joule heat." Why does electricity create heat? This is because the atoms within a substance are always moving due to their electrons: "thermal vibration." Heat and thermal vibration have a positive correlation. When an object is heated, its atoms move more. In this way, resistance and using resistors "cools" your current by slowing down the speed of movement and therefore heat.
One metaphor for this relationship is an engine. As you accelerate in your car, alternating speeds, you generate resistance. Your car is going to generate more heat as a result than it would at a constant or resting speed.
The metaphor explained in the book is a train station. As the train station gets busier, it is harder and harder to cross and get to your destination due to the traffic. This would create great heat with its greater resistance.
Question 2:
Why is it warm near an incandescent light bulb?
As the temperature of metal increases, resistances increases as well. When this resistance occurs and the temperature is increasing as well, naturally, heat is generated as a result. We can see this heat in the form of infared light. We can also call this "thermal emission." Typical lightbulbs heat up as a result of their metal components, increasing temperature, and increasing resistance, and therefore, production of infared heat waves.
Question 3:
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?
When there is no resistance at all (no heat), the atoms are allowed to move freely and with ease.
According to superconductors.org, MRI is one of the most common examples for the use of a superconductor. Here is a quote from the website describing this superconductive process: Doctors need a non-invasive means of determining what's going on inside the human body. By impinging a strong superconductor-derived magnetic field into the body, hydrogen atoms that exist in the body's water and fat molecules are forced to accept energy from the magnetic field. They then release this energy at a frequency that can be detected and displayed graphically by a computer.
According to http://www.supraconductivite.fr/, you can create a superconductor at home with a magnet and liquid nitrogen. You would need to cool down the magnet with the liquid nitrogen (remember, the superconductors have zero heat!). This magnet can be so powerful that it can levitate, according to the website.
Question 4:
What is Ampere's Law?
The book states that Ampere's Law is the phenomenon of magnetic fields moving around a wire in a circular direction. There is a polarity, however, associated with Ampere's Law, so the wires will move current in one of either two directions.
Question 5:
If current of the same size flows in the same direction in two electric wires placed side by side, what happens?
The two electric wires will attract to each other and combine to form one, larger magnetic field (as long as the current is facing the same direction).
Question 6:
What happens if current of the same size flows in opposite directions in two electric wires placed side by side?
However, if the currents flow in different directions in the wires, they will cancel each other out. Essentially, they "disappear" according to the text book.
Question 7:
Please read about Flemings Left and Right Hand Rule. Think about this Rule with respect to the motors we have made this week.
Fleming's Left and Right Hand Rule applies to DC motors. Force, magnetic field, and current are on a triple axis. Similar to my accelerometer, these will flow in three connected but different directions. If you were to stick out your left hand for example (left hand rule), and point: the magnetic field would flow in the direction of your index finger, the force would flow from your thumb, and the current would flow from your second finger next to your index finger (slightly different than magnetic field).
Left hand rule determines the direction that a motor turns. The current of a DC motor flows toward the battery (upward).
The right hand rule can be used to determine the direction of current from an electric generator.
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