Why is there no potential difference between the two ends after the component is short circuited wit

You can understand it this way, when the component is short-circuited with a wire, the wire is connected to the element in parallel and then connected in the loop, and the parallel resistance after parallel connection will be infinitesimal or even close to zero, so the current is basically all flowing through the wire, and the current of the component is close to zero, we say that the wire is short circuited to the component.

Why is it said that when the wire is connected in parallel with the component, the parallel resistance will be infinitesimal and tend to zero?

We know that the resistance of the wire is not only related to its own material, but also to the cross-section and length of the wire. i.e. =rs l, at this time there is r==l s, (you can check the resistivity of the wire, and then calculate the resistance of the wire you use.)

Because the resistivity of the wire is very small, and the wire of the short-circuit element is also very short, at this time the whole molecule tends to be infinitesimal, so the resistance of the short-circuit wire can be regarded as an ideal element, that is, the zero resistance value of the wire, since the zero resistance value, then when the current flows, there is no voltage drop, then the potential of each point in the wire is equal, so the potential of both ends of the same wire is the same.

There is also an understanding that the resistance value of the component is much greater than the resistance value of the wire, and the entire parallel resistance is also close to zero, hehe!

The resistance of the wire is small, the resistance of the component is large, and it can also be seen from the domestic electrical equipment and transmission lines, we know that the low-voltage 380V distribution network is composed of distribution transformers, transmission lines and electrical equipment. The electric energy is transmitted over a long distance through the transmission line, and the voltage from the transformer outlet end is about 380V, and the voltage to the user end is still about 380V, which shows that the resistance value of the transmission line is extremely small, and the voltage drop of the whole line is also very small, so as to ensure the working voltage of our electrical equipment. If the wire is very short and short, then the resistance will be infinitesimal, hehe, like the short wire used in this example!

In short: the electric potential at both ends is equal, as well as the equipotential, which is said in an ideal state, mainly for the sake of calculation. In a real circuit, it is impossible to equipotential and there is a potential difference.

After the component is short-circuited with a wire, the two ends of the component are equipotential points, that is, the voltage difference between the two ends is 0, and there is no potential difference. It can also be understood as: the resistance of the wire is 0, then the voltage u=ir=0.

After the two ends are short-circuited, they become the same potential, and there is no potential difference.

You can judge the voltage at both ends of R2 and the voltmeter, if the voltage is 0, the current will not pass through this branch.

i=u/r=0/r=0）

The first thing you need to understand is that the conductor is considered to have a resistance of 0, as long as there is no electrical connection in the middle, the voltage between any two points on the wire is 0, and the potential of any two points can be considered to be the same high (u=i*).

r=i*00) Since S1 is closed, the potential at the left end of R2 is as high as the positive end of the power supply. Similarly, the potential at the right end of R2 is equal to the potential at the positive end of the power supply. So the voltage at both ends of R2 is 0, so the current will not pass through.

Similarly, the voltage at both ends of the voltmeter is also 0, so no current will pass through.

In fact, the principle of short circuit is this: the short-circuited wire maintains the potential difference between the two ends of the short-circuited electrical appliance at 0