🔍 Key Concepts

• Ohm’s Law for resistance of a conductor (R = ρL/A) • Relationship between diameter, radius, and cross‑sectional area of a wire • How changing area affects resistance when length and material stay the same

💭 Think About

• If the length and material of the conductor remain the same, which parts of the resistance formula can change? • How does the cross-sectional area change when the diameter is doubled? (Think of the area of a circle in terms of radius or diameter.) • Once you know the factor by which the area changes, by what factor must the resistance change, given the inverse relationship?

✅ Before You Answer

• Write and use the formula R = ρL/A and identify which terms are constant. • Compute the new area when the diameter is doubled and compare it to the original area. • Confirm that the final choice you pick correctly reflects both the numeric change in resistance and the inverse relationship with area.