Chapter 374

Du yuan saw Shen Yan holding his fists and thumbing for a long time, but he couldn't help smiling.

How lovely

"You made the wrong gesture." Du yuan spread out his left palm, "this step is the Lorentz force, you should judge the direction of judgment with your left hand."

Shen Yan's brain is a little confused, knowledge points mixed together, he can't distinguish: "isn't the left hand ampere force? Ah, no, is Ampere's rule like a right hand? "

Du yuan chuckled: "how do you mix several concepts together?" He took the scribble paper and drew a virtual magnetic field with a pen. While using his hand to draw the posture, he patiently explained: "the left hand is related to the force, and the right hand is related to the magnetic induction line..."

Shen Yan was suddenly enlightened. Looking at the knowledge structure diagram deduced on the draft paper, the just confused knowledge points became clear and systematic.

"In fact, if you really can't do this problem, put the formula on it." Du Yuandao said, "you see, this problem all shows the diagram of electric charge in electromagnetic field. You can't be wrong if you blindly use a Lorentz formula?"

"The second question requires current. You should use the ampere force formula according to your feeling. Here, if you pile up these formulas and copy the data again, you can get at least three points. "

"In the examination room, if you can get one more point, you will get one more point. Even if you don't understand a big problem like physics, you have to gather a few formulas to cheat some points."

Shen Yan said with a smile: "how do I think you are so treacherous?"

"It's common sense." Du yuan flicked Shen Yan's forehead.

"Ouch..." Shen Yan rubbed his forehead and gave an exaggerated cry. He bent his fingers to play Du yuan, but the latter turned his head away smartly.

"Come here for me!" Shen Yan throws the book aside and holds Du yuan's hand to play him. But after playing for a long time, he didn't succeed once. On the contrary, he was hit several times by Du yuan.

Shen Yan was a little angry: "don't play!"

"Oh, don't be angry. I'll let you play it once." Du yuan put his head together.

Shen Yan turns his anger into joy and reaches out his fingers.

However, just about to play, Du yuan suddenly stood up from the sofa and went straight to the kitchen, laughing: "Oh, it's more than ten o'clock, it's time to make lunch."

"You stop!" Shen Yan realized that he had been fooled. He was so angry that he stood up to catch up.

All the way to the kitchen, Shen Yan grabs Du yuan's head with his arm, seizes the opportunity, curls his fingers and flicks them on people's forehead. Every time, he can use his strength.

"Ouch! Brother Yan spared his life... " Du yuan hugged Shen Yan's waist and said sadly, "I'm wrong..."

Shen Yan's body was stiff, and suddenly he felt that his posture was a little ambiguous. Du yuan's head was pressed down by him, almost next to his crotch.

How embarrassing!

Shen Yan suddenly released his hand and said with a red face: "do you dare?"

"I dare not." Du yuan came pitifully and said, "my forehead hurts. Do you think it's all red?"

When Shen Yan saw it, he was really red.

Du yuan's skin was white, and the red on his forehead was particularly shocking, as if he had been greatly abused.

"I always flick you. How can you flick me so hard?" Du Yuanyue said that he was more and more aggrieved. He puffed his cheek slightly and said, "brother Yan, you are too much."

Shen Yan was a little guilty. In addition, Du yuan used to call him by name and surname. When he was a little closer, he called him "Shen Yan". Just now, he suddenly called him "brother Yan". His heart was sharp and he trembled for a moment, and his whole body seemed to be electrified.