When exploring the relationship between the current on the resistor and the voltage at both ends, why adjust the sliding rheostat when replacing the fixed value resistor with a larger one? In order to keep the voltage constant, the sliding rheostat must be adjusted. How to adjust it? What is the principle? Isn't the series circuit a voltage divider? The ammeter is connected in series with the sliding rheostat and the fixed resistance R. when the sliding rheostat changes, the ammeter will also change. But why does it only change the voltage? When the sliding rheostat is connected in series in the circuit, the resistance becomes larger, Will the voltage it receives increase or decrease?

When exploring the relationship between the current on the resistor and the voltage at both ends, why adjust the sliding rheostat when replacing the fixed value resistor with a larger one? In order to keep the voltage constant, the sliding rheostat must be adjusted. How to adjust it? What is the principle? Isn't the series circuit a voltage divider? The ammeter is connected in series with the sliding rheostat and the fixed resistance R. when the sliding rheostat changes, the ammeter will also change. But why does it only change the voltage? When the sliding rheostat is connected in series in the circuit, the resistance becomes larger, Will the voltage it receives increase or decrease?

Can you send me the address of the previous one
1. First of all, we need to make it clear that what we are studying here is the relationship between the current of a constant resistance and the voltage at its two ends,
You don't care about the other numbers
2. We use the control variable method to control that when the fixed value resistance is replaced by the fixed value resistance with larger resistance, the voltage of the fixed value resistance will be higher than the original one, so we need to increase the resistance of the sliding rheostat, so that the voltage at both ends of the replaced fixed value resistance will be as large as the original one
3. When the resistance value of the sliding rheostat changes, the voltage and current will change, but our goal is to make the voltage at both ends of the constant value resistor smaller and equal to the original voltage, so we only say that changing the voltage does not mean changing the current, but that it does not mean that it does not mean that it does not change
4. The sliding rheostat is connected in series in the circuit. When the resistance increases, the voltage it receives will increase
The series current is equal, so I = U1 / R1 = U2 / R2. That is to say, if r1r2 is in series, if R2 becomes larger, then U2 will also become larger, so that its current can be equal to that of R1

Why does it need constant voltage and current to convert star resistance into y-resistance

If the current and voltage are not required to be constant, then you can replace it with any resistor. The purpose of transformation is to facilitate analysis, that is, after transformation, it should be equivalent to that before transformation. Only when the voltage and current remain unchanged after transformation, it can be called equivalent

What are the disadvantages of resistance sampling current / voltage conversion circuit

The resistance of the current / voltage conversion circuit with resistance sampling should be small enough in order to have enough influence on the main circuit, so that the output signal is weak and easy to be disturbed. The accuracy is not high enough

Current conversion, such as 1A =? Ma

1A=1000mA