The SI unit of resistivity is:
Ω m
Resistance is related to resistivity by \(R = \rho\frac{l}{A}\), so \(\rho = \frac{RA}{l}\).
Units: \(\frac{\Omega \times \text{m}^2}{\text{m}} = \Omega\,\text{m}\) (ohm-metre).
Ω is the unit of resistance, not resistivity; Ω/m is resistance per unit length; S/m (siemens per metre) is the unit of conductivity, the reciprocal of resistivity.
Hence, the answer is Ω m.
When a cylindrical wire made of a new alloy is stretched to double its original length, its resistance increases by a factor of four. If a second wire of the same alloy is shaped into a flat ribbon of identical length but half the original cross-sectional area, which property stays constant between the two wires?
A wire is stretched uniformly at a constant temperature without changing its material. Which of the following physical quantities remains unchanged?
Which of these changes would decrease the resistance of a metallic conductor?
Which of the following metals has the lowest electrical resistivity?
A uniform wire of resistance 9Ω is bent in the form of an equilateral triangle. Find the effective resistance across a side of the triangle.
The value of carbon resistance is 54 × 103 Ω. The percentage tolerance is 5%. What is the colour code sequence of carbon resistance?
Which of the following relations are wrong?
I. The specific conductance is given by the relation \(k = \frac{1}{R}\left( {l/A} \right)\)
II. The equivalent conducting is given by the relation \(\lambda = \frac{{100\;K}}{C}\)
III. The specific resistance is given by the relation \(\rho = \frac{{Rl}}{A}\)
A current is flowing through a metallic wire. If the wire is heated, which quantities change?