Week 14 Blogpost

 

The big question addressed in the lab and a description of what you did.

• Driving Question: How do we power clocks and other devices?

In the lab today, we began with a warm-up activity that made us think about what circuit "series" or "parallel" would be used to wire a house. Our group decided that we would use a parallel circuit because each lightbulb in a parallel circuit gets the full energy and voltage out of the lightbulb, and you can turn a light off without the other lights in the house being affected. We then tested these circuits using the STEM snap circuits in the lab, where we confirmed that we should use a parallel circuit because you can take out a lightbulb and the other lightbulb isn't affected, whereas in a series circuit, you take out a lightbulb and the other lightbulb turns off. Then we talked about circuit rules. We understood the differences between electric conductors and insulators, where in conductors, electrons move freely between atoms, while in an insulator, electrons are tightly held by atoms. Something important I found about a series circuit is that energy is being shared between both lightbulbs, causing the rate of energy transfer to decrease, whereas in a parallel circuit, both lightbulbs have a direct connection to the battery, causing the rate of energy transfer to increase. Courage used a great water analogy that helped me make sense of what is happening inside the battery and lightbulb while working in a circuit. I enjoyed the analogy that a battery is like a person scooping the water back into the bucket, because it helped me understand that energy must continue to be transferred to the electrons, helping keep them flowing through the circuit. We then briefly discussed our Unit "Storyline" and what we have done in each unit building up to our final lesson discussing wind turbines. This part of the lab helped me review what we have covered so far in this unit and reminded me of the important concepts related to electricity. We then started the "KidWind" Turbines, which deal with generating electricity. As a group, we designed our own wings for a turbine. We designed multiple sets of wings, where we were able to light up an LED light. We also tested the voltage of our turbine, which reached 2 volts. Through this experiment, I learned that the design of the turbine wings is critical in producing electric currents. The way the windmill works is through the air moving, which has energy, causing the windmill's wings to move, which produces even more energy through electric currents. The energy is then transferred through the wires, producing electricity.  We weren't able to completely finish our lab lesson for the day, but valuable learning was still taking place. 

A description of what you learned in Thursday's lecture.

 In the lecture today, we talked about how swings and windmills have something in common, which is the transfer of energy. With a swing, a person is physically pushing the swing using energy, then the swing starts to move, producing energy, then causing the air to move, whereas in a windmill the air moves to physically move the windmills, producing energy, then the energy produced from the windmill cause an electric current, which transfers energy into the wires, helping create electricity. We then discussed how we want students to be able to talk about and explain how energy can be transferred from place to place through electric currents. I learned that magnetic fields can make electric charges move! We also explored in depth how the Windmill turns a generator, and inside the generator, there is a magnet around the entire outside with a north and south, that had a coil of wire on the inside. When the coil is turned through the shaft with the moving wire, it ends up making the electrons move through because it's traveling through a magnetic field. Something important I learned is that every generator is a motor, and every motor is a generator. Another important concept is that the changing magnetic fields cause electrons to move in a wire, which is called electromagnetic induction. For example, in an induction cooktop, there is a powered electromagnet under the cooktop which causes a changing magnetic field, which causes electric current loops, "eddy currents," which heat the metal of the pan and not the surface. Our world runs on electromagnetic induction. Other examples for the use of electromagnetic induction are for charging devices, making efficient cars, and nuclear power plants. 

Answer questions about the weekly textbook reading:

1.  What did you learn?

• Moving charges exert forces on other moving charges, which helps explain why nearby current‑carrying wires attract each other.​

• A coil of wire with current behaves like a magnet, and a permanent magnet can be thought of as many atomic “current loops” created by electron spin, all lined up.​

• Electromagnetic induction is essentially the situation of moving electrons in a magnet interacting with electrons in a nearby wire, making them move and creating current.​

• Most everyday electricity (from wind, water at dams, steam turbines, and home generators) is produced by spinning coils of wire near magnets using electromagnetic induction.​

• The same interaction in reverse underlies electric motors, where current in coils near magnets produces motion instead of electricity.

2. What was most helpful?

• The hands‑on transformer activity showing two adjacent wires attracting each other made the idea “moving charges push on other moving charges” very concrete.

• The everyday examples (windmills, dams, fossil‑fuel and nuclear plants, small generators, toy train motors) showed that this single principle underlies most power generation and many devices.​

• The idea that a permanent magnet behaves like many tiny aligned current loops due to electron spin helped make the magnet-to-wire analogy understandable.

3. What do you need more information on?

More information and detail on how electron spin and atomic structure produce the large‑scale magnetic fields of permanent magnets could help clarify for me the micro to macro connection. 

4. What questions/concerns/comments do you have?

A question I have been left with is, what (if anything) limits how much current a generator can produce, and how design (number of turns, rotation speed, magnet strength) influences real‑world power output? I also found it interesting how the author of the article notes that science does not really explain “why” induction ultimately happens, only “how” it behaves.