If the length of a wire is increased by a factor of 2, its resistance will also increase by a factor of 2. This is because the resistance of a wire is directly proportional to its length. In other words, the longer the wire, the greater its resistance.

The formula for calculating the resistance of a wire is:

```

R = ρ * (L/A)

```

where:

* R is the resistance of the wire in ohms (Ω)

* ρ is the resistivity of the wire in ohm-meters (Ωm)

* L is the length of the wire in meters (m)

* A is the cross-sectional area of the wire in square meters (m²)

As you can see from the formula, the resistance of a wire is directly proportional to its length. This means that if you double the length of a wire, you will also double its resistance.

Conversely, if you decrease the length of a wire, you will also decrease its resistance. For example, if you cut a wire in half, you will also cut its resistance in half.

The resistance of a wire is also affected by its resistivity and its cross-sectional area. Resistivity is a measure of how much a material resists the flow of electricity. The higher the resistivity of a material, the greater its resistance. Cross-sectional area is the area of the wire that is perpendicular to the flow of electricity. The greater the cross-sectional area of a wire, the lower its resistance.