Question

The same potential difference is applied across two wires. Wire A carries twice thecurrent of wire B. If the resistance of wire B isR, what is the resistance of wire A?

Answer 1

Answer:

R / 2

Explanation:

According to Ohm law, the current flowing within the resistor is the ratio between the potential difference and the resistance:

$I = \frac{V}{R}$

So if wire A carries twice the current of wire B, while their potential is the same then:

$I_A = 2I_B$

$\frac{V}{R_A} = \frac{2V}{R_B}$

$R_B = 2R_A$

$R_A = R_B / 2 = R / 2$