When 3V voltage is applied at both ends of a conductor, the current passing through the conductor is 0.2A, and the resistance of the conductor is______ When a voltage of 6V is applied at both ends of the conductor, the resistance of the conductor is equal to______ Ω．

When 3V voltage is applied at both ends of a conductor, the current passing through the conductor is 0.2A, and the resistance of the conductor is______ When a voltage of 6V is applied at both ends of the conductor, the resistance of the conductor is equal to______ Ω．

(1) The resistance of the conductor: r = UI = 3v0.2a = 15 Ω; (2) because the resistance has nothing to do with the voltage at both ends of the conductor, when the voltage at both ends of the conductor is 6V, the resistance of the conductor is still 15 Ω

When 6V voltage is applied at both ends of the resistance, the current passing through the conductor is 0.2A. If the voltage at both ends of the resistance is adjusted to 3V, the current passing through the conductor is 0.2A______ When there is no current, its resistance is______ Ω．

(1) ∵ u = 6V, I = 0.2A, ∵ the resistance of the conductor is r = UI = 6v0.2a = 30 Ω; and ∵ the resistance of the conductor has nothing to do with the voltage at both ends and the current passing through it, ∵ when the voltage at both ends of the conductor changes to 3V, that is, when the voltage U ′ = 3V, the resistance of the conductor remains unchanged and is still 30 Ω, then the current passing through the conductor is I ′ = u ′, r = 3v30 Ω