Derivation of physical capacitance formula for senior two students C=εS/4πkd How does the 4 π K on the denominator come out? Try to make it easier to understand~

Derivation of physical capacitance formula for senior two students C=εS/4πkd How does the 4 π K on the denominator come out? Try to make it easier to understand~

4 π is just a constant. In fact, when you go to college, you will understand the origin of this formula. You said, "the capacitance C of parallel plate capacitor is directly proportional to the dielectric constant ε, is directly proportional to the opposite area s, and is inversely proportional to the distance d between the plates." they are just a proportion. It's just a proportional relationship

Why is the relationship between the maximum value and the effective value in alternating current root 2, and how to deduce it

If you are not a college student, just remember the root 2. If you want to know more, just try to get into the University. If you are a college student, just look at the picture given to you downstairs. There is no more clear picture,

How many times of RMS is the maximum value of sinusoidal alternating current equal to?
If the effective value of sinusoidal alternating current is 220 V, what is the maximum value equal to?

The maximum value of sinusoidal alternating current is 220 ×√ 2 ≈ 311.12v