Some formulas of equilateral triangle I only know that the two heights are √ 3 × A / 2 The area is √ 3 × a ^ 2 / 4 I forgot a few others. It's like the root of two times six times a is the distance from the center to the vertex

Some formulas of equilateral triangle I only know that the two heights are √ 3 × A / 2 The area is √ 3 × a ^ 2 / 4 I forgot a few others. It's like the root of two times six times a is the distance from the center to the vertex

√ 3 × A / 3 distance from center to vertex
3 × A / 6 distance from center to bottom

Why is the force acting on two circular conductors in the same current direction attractive? Can the circular conductor be regarded as a straight conductor?

It is equivalent to two electromagnets. Judging by the right-hand spiral rule, the magnetic fields of the two electromagnets are in the same direction. If we think of the two ring currents as two magnetic needles, we can see that the N pole of one magnetic needle is close to the S pole of the other, and they attract each other
Note: the premise is that the two ring wires are arranged in parallel
At this time, the two circular wires should be regarded as magnets or needles. If they are regarded as straight wires, it is more difficult to understand,
But in fact, even if it is a straight wire, with the same current is still attractive

If the current direction of two parallel wires is the same, are they close to each other or repel each other

Close to
First, use the right-hand rule to judge the magnetic field direction of one of the wires,
Then the left-hand rule is used to judge the direction of another wire
The mobile phone is not easy to operate. Let's call it a day

When the current direction of two parallel electrified straight wires is the same, what is the distribution of the current in the two wires to both sides?
Can it be solved by Ampere force or by magnetic coupling?

It can be explained by Ampere force. It is also the cause of magnetic field coupling. Suppose that these are two wires ♁ ♁ according to the right-hand spiral rule, the magnetic field generated by the left wire is clockwise, the right wire is in a downward magnetic field, the electron flow in the right wire is outward (opposite to the current direction), and the electron flow through the magnetic field is

Why do parallel electrified straight wires attract the same direction current

You let one wire form a magnetic field, and the other wire is in the magnetic field. Just judge the motion of the wire. The right hand sets the magnetic field, and the left hand sets the direction of motion

Effective length of magnetic induction line cut by conductor
How to judge. Why, mainly to say why, to judge probably all know. You can use this graph to explain why the effective length on the graph is not the radius? Why is the notch

It's about differentiation. I can only talk about it in a vulgar way, but you just need to remember the part of the gap
Moving to the left, GH section generates induced electromotive force. Through rough judgment of the right hand, assuming that there is current, the current direction is g to h, where h is the positive pole of induced electromotive force and G is the negative pole
Let's look at the Ge segment and FH segment again. According to the rough judgment of the right hand, the current direction is from G to e, then E is the positive pole and G is the negative pole. The same is true for FH segment, where f is the positive pole and H is the negative pole
The EMF generated by this ring is positive and negative, so it is partially offset, and the rest is just the part of the gap
To put it more crudely (personal understanding)
After the gap is closed, the magnetic flux does not change and no induced electromotive force is generated when the magnetic field moves. The effective length between the gaps is the part of the gap

Determination of effective length of magnetic induction line cut by conductor
It is best to give a few examples of irregular rectangular combination diagram and incomplete original wireframe

Because the effective length of closure is 0, the irregular connection of two ends directly is equivalent to the original coil potential
be just reversed

How to determine the effective length of the magnetic induction line cut by conductor? As shown in the figure. See the effective length of the magnetic induction line cut during the movement, please explain in detail
 

When all the closed coils enter the magnetic field, the effective length is 0,
When the right half of the triangle enters the magnetic field, the effective length is the direct line between the two points just entering the magnetic field, and the effective length increases
When the left half of the triangle enters the magnetic field, the effective length is the direct line between the two points just entering the magnetic field, and the effective length decreases

The effective length of magnetic induction wire cut by isosceles trapezoid wire frame
The isosceles trapezoid wire frame with the upper bottom of 5L, the lower bottom of L and the height of 2H starts to fall from static state. In the process of falling, it passes through a uniform magnetic field with the height of H and the length of infinity (i.e. rectangular magnetic field, but there is no boundary on the left and right sides). Q: in the process of trapezoid falling, during a period of time when the lower bottom passes through the magnetic field and the upper bottom does not enter the magnetic field, Does the effective length of the magnetic induction wire cut by trapezoidal wire frame change? What is the effective length?
What is the effective length of the trapezoidal cutting magnetic field line at the moment when the top and bottom edge enter the magnetic field?
Why?
How did you get it?
I just don't know how to get 2L and 3L? The upper sole is 5L and the lower sole is L. how do the effective lengths of 2l and 3L come from?
Second floor, 2L. How did you get it? Why is the effective length perpendicular to the magnetic induction line always 2L? Is it from the geometric relationship of isosceles trapezoid! Make me clear! It's best to have a picture!
And you said, the second question is the first question plus the length of the bottom, why is the length of the top and bottom 1L?
On the third floor, how do you understand the 3L of your second question? Why is the current going in the opposite direction, so subtract? Why is 5L minus 2L? I still don't know how to get that 2L.
As long as I understand how the 2l came out, I should be able to understand how the 3L came out. Who can understand me! Tell me step by step~

1. In the process of trapezoid falling, the effective length of the magnetic induction line cut by trapezoid wire frame does not change during a period of time when the lower bottom edge passes through the magnetic field and the upper bottom edge does not enter the magnetic field, and the effective length is 2L
The length of the middle part of the upper bottom is l, and the length of the two sections on both sides is 2L
Assuming that the magnetic field just comes out of the bottom, the length of the upper edge of the magnetic field between the two perpendicular lines and the two waists is l (which is the median line of the two right triangles), and the length of the two parts is the effective length of the magnetic induction line cut by the two waists, that is, 2L
Before the top and bottom enter the magnetic field, the effective part of the length of the cut magnetic induction line remains unchanged
2. When the top and bottom edge enter the magnetic field, the effective length of trapezoidal cutting magnetic field line becomes 3L
Because the length of the upper sole is 5L, and the effective length of the magnetic induction line cut by the two waists is 2L, but the direction of the induced electromotive force generated by the magnetic induction line cut by the two waists is opposite to the direction of the induced electromotive force generated by the magnetic induction line cut by the upper sole, so the length of 2l will offset each other, so the effective length of the induced electromotive force generated at this time is: 5l-2l = 3L

On the problem of cutting the effective length of magnetic induction line,
I mainly want to ask about the effective length of the cutting magnetic induction line inside
First of all, for the first time, the answer is that the effective length of the cut magnetic induction line is the sum of m1a and N1b. Why?
Isn't both m1a and N1b out of the magnetic field? How to say that the effective length of the cut magnetic induction line is the sum of m1a and N1b?
I can understand everything else, but I can't understand the effective length here

In the figure above, V is the direction of AB cutting magnetic line of force, a ` B 'is perpendicular to V, and the line segment a ` B' is the effective length of AB cutting magnetic line of force
The effective length is B ` C`