Answer:
Option A
Explanation:
Resistivity, electrical resistance of a conductor of unit cross-sectional area and unit length. A characteristic property of each material, resistivity is useful in comparing various materials on the basis of their ability to conduct electric currents. High resistivity designates poor conductors.
The resistivity of an exceedingly good electrical conductor, such as hard-drawn copper, at 20° C (68° F) is 1.77 × 10-8 ohm-metre, or 1.77 × 10-6 ohm-centimetre. At the other extreme, electrical insulators have resistivities in the range 1012 to 1020 ohm-metres.
Good electrical conductors have high conductivities and low resistivities. Good insulators, or dielectrics, have high resistivities and low conductivities. Semiconductors have intermediate values of both.
