Assertion: The resistivity for a substance is its resistance when it is one meter long and its area of cross-section is one square meter.
Reason: The SI units of resistivity is ohm meter (m).
Answer & explanation
Correct answer: option 1
R α \(\frac{l}{A}\)
R = ρ\(\frac{l}{A}\)
ohm = ρ\(\frac{1m}{1m^2}\)
ohm m = ρ