Final answer:
When a wire is stretched to twice its original length, its resistance quadruples to 4 times its original resistance, assuming the volume remains constant.
Step-by-step explanation:
The resistance of a wire, when stretched to twice its original length, can be determined using the formula for resistance R = ρ(L/A), where ρ is the resistivity, L is the length, and A is the cross-sectional area. Since the volume remains constant and the wire is stretched to twice its length, the cross-sectional area is reduced by a factor of 4. Therefore, the new resistance Rstretched = 4R.