Answer: 30 ohms
Explanation:
Potential difference (Voltage) = 12 V
Wire resistance = ?
Current, I = 0.40A
Recall that Voltage = Current x Resistance
i.e V = I x R
12 volts = 0.40A x R
R = 12 volts / 0.4 A
R = 30 ohms
Thus, the resistance of the wire is 30 ohms