A potential difference of 12 V is found to produce a current of 0.40 A in a wire. What is the wire's resistance?

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