Experiment on the relationship between current and voltage resistance To explore the relationship between current and voltage is to control the conductor resistance unchanged, and use sliding rheostat to change the voltage. However, when the sliding rheostat resistance is increased, the total resistance in the circuit will be increased, and the current will be naturally small. How can we know that it changes with the voltage There is also why not directly use the ammeter and voltmeter to measure the current and voltage of the sliding rheostat, so that the power supply voltage does not change, but you can change the resistance value through the jumping rheostat, and then measure the relationship between the current and resistance. Is it because the circuit can not be protected

Experiment on the relationship between current and voltage resistance To explore the relationship between current and voltage is to control the conductor resistance unchanged, and use sliding rheostat to change the voltage. However, when the sliding rheostat resistance is increased, the total resistance in the circuit will be increased, and the current will be naturally small. How can we know that it changes with the voltage There is also why not directly use the ammeter and voltmeter to measure the current and voltage of the sliding rheostat, so that the power supply voltage does not change, but you can change the resistance value through the jumping rheostat, and then measure the relationship between the current and resistance. Is it because the circuit can not be protected

What we study is the change of the current in the constant value resistor with the voltage at both ends of the constant value resistor, not that of the sliding rheostat. When the sliding rheostat is adjusted, the voltage at the two ends of the constant value resistor changes, and the current changes with the change, which is in positive proportion