"Since everyone just finished their lunch break, I'll start with a simple question to get everyone used to it."

"In the circuit shown in the figure, three identical bulbs a, b, c and inductors L1 and L2 are connected to the DC power supply, and the resistance of the inductors is negligible. Electric key S from

When the closed state is suddenly disconnected, which of the following judgments is correct? ”

"A. A first lightened, then gradually darkened."

"B.b first brightens and then gradually darkens."

"C.c first brightens and then gradually darkens."

"D.b, c, are getting darker."

In class, a middle-aged woman patiently drew a circuit diagram on the blackboard with chalk, and then swept the class with a serious gaze as usual, looking very stern.

The lady wore a well-fitting suit, rolled her sleeves up twice for the sake of writing, combed her hair neatly, and wore thin-framed square glasses, and she looked smart and powerful.

"Since there are new students coming today, let's ask our new students to answer this question."

After inspecting the entire class, the middle-aged lady's gaze accurately projected to Shi Yun's side.

"Did she say you or me?"

Lin Hagi smirked professionally, his mouth did not move and he secretly spoke, a physics book blocked his fingers, and then secretly poked Shi Yun's back.

Because Lin Hagi was sitting behind Shi Yun, he didn't know who the physics teacher was referring to for a while.

The young man didn't hesitate, and stood up directly, causing Lin Hagi to secretly rub his outstretched fingers not only fell into the air, but also directly exposed his outstretched fingers to the sight of the teacher on the stage.

Hayashi Hayashi: !!

Hayashi: You don't say a word when you get up!!

When it comes to critical times and formal occasions, Yun naturally won't be foolish.

The young man understands the principle of respecting teachers. So in response to the teacher's words, Shi Yun straightened his small waist, raised his head and chest, and replied with a smile.

"The effect of the inductance coil on direct current is: the resistance value is large at the moment when it is turned on, and the resistance is zero after it is turned on, which is equivalent to the power supply at the moment of disconnection."

"When the electric bond S is closed, the current in the inductor L1 is equal to twice the current of L2, and at the moment when the electric bond K is disconnected, due to the self-inductance, the two inductance coils are equivalent to two power supplies, and the three bulbs form a closed loop, and the current through b and c passes through a, so a first brightens, and then gradually darkens, so A is correct."

"b, c bulb gradually decreases by current i, b. c is wrong, d is correct."

"That's why I chose AD for this question."

Of course, the main reason for being able to smile is because Shi Yun still knows this question, otherwise how could he stand up with a "pout".

"Good. Shi Yun's answer was perfect, and I liked it very much. ”

The teacher on the stage smiled with some relief, although he was still so stern, but after laughing, the whole person was a lot gentler.

"You may be seated."

"Little devil, why are you standing so fast, this is not your style!"

Lin Hao watched Shi Yun sit down, and then secretly hid behind Shi Yun to block his face and asked.

Shi Yun showed an intriguing smile and was silent, and the corners of his lips rose even more when he heard the next sentence.

"Then let's ask this Lin Ha, who is sitting behind Shi Yun, to answer the next question."

...... "Me?"

Lin Hagi was stunned in his seat for a few seconds before standing up.

The teacher on the stage gave up handwriting, opened the PPT directly, projected a big question on the screen, and read the question again.

"As shown in the figure, the magnitude of the magnetic induction intensity of the uniform magnetic field is that the horizontal insulating sheet in the magnetic field in the B magnetic field and the left and right boundaries of the magnetic field intersect vertically at M and N respectively, and MN=L. The particles will be rebounded when they hit the plate (the collision time is very short), the horizontal division degree before and after the rebound remains unchanged, and the vertical velocity grinding size remains unchanged and the direction is opposite."

"The velocity of a particle with a mass m and a charge amount of -q is fixed, and the magnetic field can be injected horizontally from different positions on the left boundary, and the radius of circular motion in the magnetic field is d, and d

"Find: The particle injected from point P finally emits the magnetic field from point Q, PM-d, QN= 2, and find the time t of the particle movement from P to Q."

“……”

Shouldn't there be two questions in front of this kind of question???

Why do you just ask the last fateful question?!

I can't answer how embarrassing this little master is!

Master, my first name!!

ㄟ (θ_θ) plant

"The first two questions are not interesting, so just come to the third question, and if you want to use the answers to the first two questions, you can do some mental calculations."

The teacher probably saw what Lin Hagi was thinking.

“……”

- After three minutes

"You can talk about your thoughts first."

The teacher said that taking a step back and the sea is wide.

"......" has no ideas......

Hayashi said that taking a step back is still a dead end.

Shi Yun sat in his seat and smiled extraordinarily brightly.

This is to let the newcomers answer the questions again, of course, the sooner you stand up, the easier the questions!

Touching my little brain, I'm really smart again!

(*•̀ᴗ•́*)و ̑

Fortunately, I just stood up, otherwise I wouldn't have done this question now, and it would be a shame to stand still and not answer it like the second son!!

I don't want the character of the domineering president!!