Question

The reciprocal of resistance is conductance. The unit of resistance is ohm. Therefore, the unit of conductance is:
(A) ohm
(B) henry
(C) per ohm
(D) moles/litre

Answer 1

Hint
We will first analyse the relation between resistance and conductance and then decide the unit for conductance based on the unit for resistance. As, conductance is the reciprocal of resistance. The unit for conductance will also be the reciprocal of the unit for resistance.

Complete step by step answer
According to the question we have: -
$\Rightarrow \operatorname{Re} si\tan ce = \dfrac{1}{{Conductance}}$
Now, if the unit for resistance is given ohm $(\Omega )$ and conductance is the reciprocal of resistance, the unit for conductance will also be reciprocal to the unit for resistance. Therefore, the unit for conductance becomes per ohm $({\Omega ^{ - 1}})$ .
Hence, option (C) is the correct solution.

Note
In the question, instead of per ohm, it could also be written inverse ohm which is the same thing and hence also correct. Other widely used names for the unit of conductance in addition to ‘per ohm’ are ‘mho’ and ‘Siemens’.