In the experiment of exploring Ohm's law, the relationship between current and resistance should be explored. To keep the voltage unchanged and change the resistance, the function of slide is to adjust the resistance by adjusting the current Slide the rheostat to keep the voltage constant, so why can it keep the voltage constant? What's the principle?

In the experiment of exploring Ohm's law, the relationship between current and resistance should be explored. To keep the voltage unchanged and change the resistance, the function of slide is to adjust the resistance by adjusting the current Slide the rheostat to keep the voltage constant, so why can it keep the voltage constant? What's the principle?

In physics, the control variable method is used to study the relationship between a quantity and several other physical quantities
The relationship between current and resistance, so we should keep the voltage at both ends of the resistance unchanged and change the resistance, so as to observe the quantitative relationship between current and resistance,
As for why it can keep the voltage unchanged? This problem is understood in this way. The resistance and sliding rheostat are in series. When we change the constant resistance, the voltage at both ends of the resistance changes correspondingly. However, the control variable method requires us to ensure that the voltage of the constant resistance remains unchanged, and the total voltage remains unchanged according to the series voltage division, By adjusting the sliding rheostat, the voltage at both ends of the setting voltage can be changed!

Ohm's law of constant resistance how to explore the relationship between current and voltage, what is the operation method

A variable voltage power supply, a fixed resistance, an ammeter and a single pole switch are connected in series. The voltmeter is connected in parallel at both ends of the resistance. Turn on the switch, adjust different power supply voltage, record the readings of the corresponding voltmeter and ammeter, and make U-I diagram. Pay attention to the range of the voltmeter and ammeter during operation