The correct answer is A. p.
How can you solve the resistivity of the two parts?
Resistivity (ρ) is a property of the material itself and doesn't depend on the shape or size of the conductor. It reflects the inherent resistance of the material per unit length and cross-sectional area.
When you cut a wire into two equal parts, you divide the total length (l) by two, but the cross-sectional area (A) and material resistivity (ρ) remain the same.
The resistance (R) of a conductor is related to its length (l), cross-sectional area (A), and resistivity (ρ) by the following equation:
R = ρ * l / A
Since the length is halved, the resistance of each individual part becomes:
R part = ρ * (l/2) / A = ρ * l / (2A)
Comparing the resistance of each part (R_part) to the original resistance (R):
R part = R / 2
Therefore, even though the resistance of each part is half the original resistance due to the shorter length, the resistivity remains the same for both parts and is equal to the original resistivity (p).
So, the answer is A. p.