The formula r = u / I can be derived from Ohm's law? When the voltage increases, the resistance also increases. When the current increases, the resistance decreases. When the voltage is zero, the resistance is zero. The resistance is determined by the nature of the conductor itself and has nothing to do with the current and voltage.

The formula r = u / I can be derived from Ohm's law? When the voltage increases, the resistance also increases. When the current increases, the resistance decreases. When the voltage is zero, the resistance is zero. The resistance is determined by the nature of the conductor itself and has nothing to do with the current and voltage.

The resistance value of the resistance is constant when the temperature is constant. The resistance value of the resistance is related to the material and temperature. It is about R = resistivity × length △ area. The influencing factors of the resistivity are the material and temperature

According to Ohm's law, the formula r = u / I can be derived. The following statement is correct: a when the voltage U increases by 2 times, the resistance R also increases by 2 times; B when the current I increases by 2 times, the resistance R decreases by 1 / 2; C when the current through the conductor is zero, the resistance is zero; d when the voltage at both ends of the conductor is zero, the resistance is not zero

D