I am the cook, but I am Li Er's son-in-law

Li Shimin will not stop Li Shu from learning these things.

In his opinion, this is the same as his other children, they are sensual, and Li Shu and Li Lizhi are just entertaining in another way.

Girl, I don't expect her to appear in the future.

Yin Xuan looked at Li Shimin.

This question looks simple, but it is very difficult to explain, because I can't come up with anything that can prove all this.

Physics is just a science of analyzing the objective laws of the world, and mathematics is just a science of processing information.

There are also chemistry and biology. The combination of these things is the power to change a world.

Yin Xuan was silent for a while, then shook his head: "You want me to explain to you, but it's hard to convince you with words."

Li Shimin curled his lips in disbelief.

Yin Xuan changed the subject: "However, if you can get some copper wires, at least five feet long, hair-thin copper wires, and a few pinky finger-sized, pure copper or pure iron rods, and some magnets."

"I can prove to you that this knowledge is somewhat useful."

Li Shimin tilted his head back: "Copper wire? Iron rod, copper rod?"

These things are not very expensive, that is, the thin copper wires are a bit difficult to get, but for him, it is not difficult to get them.There are a lot of these things in the palace, even if they are woven into ropes, it is not a problem to get a few sets of tortoise shells.

But he doesn't quite understand, what can these things prove?
Yin Xuan nodded.

Li Shimin thought for a while, wondering whether these things were out of line for his current disguised identity.Only then did he answer: "Okay, I'll bring these things tomorrow, I hope the store can open my eyes."

Wait until the next afternoon.

Li Shimin came with these things.

Behind him were Cheng Yaojin, Wei Zheng, Duan Zhixuan and other people who watched the excitement and didn't think it was a big deal.

Li Shimin beckoned and asked the maid to put the box on the table. After opening it, there were the things Yin Xuan wanted.

"Shopkeeper, I will trouble you next." Li Shimin said with a smile.

Yin Xuan sat down, first took an iron rod, clamped two wooden boards, then wrapped them with cloth, and then wrapped copper wires round and round.

Winding copper wire is a delicate job.

Li Shimin and the others just waited like this, Cheng Yaojin wanted some food, but before he could open his mouth, Li Shimin gave him a stare, so he could only go to the door to order some fried skewers sullenly.

No wine yet.

Delicious is delicious, but this time, Cheng Yaojin, who is used to drinking in Tongfu restaurants and whose mouth has been raised, is somewhat unaccustomed to him.

He could only watch Yin Xuan roll the copper wire helplessly.

Don't dare to smack your mouth while eating, otherwise Yin Xuan's death stare will meet you.

Cheng Yaojin was wronged.

After wrapping the copper wire, he took a larger wooden board. This step was a bit difficult for Yin Xuan, who didn't know much about carpentry, so it took him a long time to fasten the magnet to the wooden board more firmly.

Then put the wound coil on the magnet, leaving about two fingers' width in the middle.

Insert the copper sheet and copper rod.

One end of the remaining copper wire is wound on the fixed copper sheet, and the other end is wound on a copper rod and an iron rod respectively.

Until this step, they still didn't understand what Yin Xuan was doing.

Yin Xuan took a deep breath, turned around, went to the kitchen to fetch a tomato, and then inserted the copper and iron rods on the tomato.

Li Shimin and the others were even more puzzled.

Judging by Yin Xuan's appearance, he doesn't plan to do anything more. Does this mean that the work has been completed?

But what does this prove.

Ingenuity?

Yin Xuan is not ingenious either. When they saw Yin Xuan doing carpentry, they were so anxious to death. If they didn't understand what Yin Xuan was going to do, they would have kicked him away and started on their own.

Before they could spit out their doubts.

With a bang, the boards bound by the copper wires turned.

Their ears could move, and after moving their ears, everyone cast their gazes over.

"Kang Dang, Bang Dang" the wooden board started to rotate, and the speed was not too fast, maybe even less than a thousand.After all, Yin Xuan did not wrap too thick a copper coil, and the current generated by the tomatoes is not too large.

But it turned around.

Yin Xuan thought for a while, found a piece of paper, folded a small windmill, and stuck it on the iron rod. A weak wind rushed towards his face, making Li Shimin and the others tremble uncontrollably.

Yin Xuan looked at this little thing with relief.

This is a "motor", commonly known as a "motor", where a current-carrying conductor is subjected to a force in a magnetic field.The principle of this thing is not complicated, and it is very simple to make.

When I was young, I played four-wheel drive. In order to overwhelm other children in the same compound, I asked my uncle for advice.

The extracurricular remedial classes of the fifth grade also let them do this.

Li Shimin and the others stared at this thing.

Until a "pop", the windmill was thrown out and hit Cheng Yaojin's face.

Li Shimin finally came back to his senses, and pointed at this thing: "Shopkeeper, what is this thing, how can it turn on its own?"

There is no wind, no water flow, just in front of them, connect a Zhu Yuguo with a copper coin, and let it turn?And it goes so fast.

Hundreds of revolutions per minute is indeed a very fast speed for them.

"This thing is called a motor." Yin Xuan waved his hand and said softly, "It's what you think is useless knowledge."

"What's the principle behind it?"

"Even if I tell you, you probably won't understand it for a while."

Li Shu looked at this thing with a thoughtful look on her face.

This is electromagnetic induction?
She remembered that Yin Xuan had mentioned this to herself.

"It's not electromagnetic induction, so don't confuse it." Yin Xuan glanced at Li Shu, and added another sentence, "I'll give you two questions later, and calculate the work done by the motor."

Li Lizhi's eyes widened.

I just watched the fun, so why do I have to do the question again.

Li Shimin looked at the small thing that was still spinning, and raised his hand to touch his chin: "It's a novelty, but it's a pity. This thing is too small. If it can be made bigger, it would be great if it can roll over."

A rollover is a waterwheel.

"Why not?" Yin Xuan asked back.

Li Shimin was stunned, and frowned: "Since we want to make it big, I don't know how much Zhu Yuguo will be used. Just to overturn the car, the gain is not worth the loss."

Yin Xuan shook his head and chuckled: "It is not Zhu Yuguo that makes the motor turn, but the energy released by the reaction between Zhu Yuguo and the iron and copper rods."

"The key is this energy, not Zhu Yuguo."

Yin Xuan paused while speaking.

"And what is this energy, how to analyze this energy, and how to grasp this energy are what I want to do in this field of study."