Question

S.I. unit of conductance is-
$
  A.{\text{ Ohm}} \\
  {\text{B. Siemen}} \\
  {\text{C. Ohm metre}} \\
  {\text{D. }}\dfrac{{Ohm}}{{metre}} \\
 $

Answer 1

Hint- In order to solve this question, firstly we must know the concept of conductance i.e. Conductance is an expression of the ease with which electric current flows through a substance. Then we will use this concept to get the required result.

Complete step-by-step answer:
Conductance is an expression of the ease with which electric current flows through a substance. In equations, conductance is symbolized by the uppercase letter G.
The ability of a system to conduct electricity, measured by the ratio of the current flowing through the system to the potential difference across it. It is reciprocal of resistance.
The derived unit of electric conductance, electric susceptance and electric admittance in the International system of units (SI). Conductance, susceptance and admittance are the reciprocals of resistance, reactance and impedance respectively, hence one siemens is redundantly equal to the reciprocal of one Ohm $\left( {{\Omega ^{ - 1}}} \right)$ is also referred to as the mho.
The unit is named after Ernst Werner von Siemens. For an element conducting direct current, electrical resistance $R$ and electrical conductance G is defined as-
$G = \dfrac{1}{R} = \dfrac{I}{V}$
Where I is the electric current through the object and V is the voltage (electrical potential difference) across the object.
The unit siemens for the conductance G is defined by-
$\left[ S \right] = \left[ {{\Omega ^{ - 1}}} \right]$ = $\left[ {\dfrac{A}{V}} \right]$
Where $\Omega $ is the ohm, A is the ampere and V is the volt.
For a device with a conductance of one siemens, the electric current through the device will increase by one ampere for every increase of one volt of electric potential difference across the device.
The conductance of a resistor with a resistance of five ohms.
Mho is the reciprocal of one ohm. It is derived from spelling ohm. The SI term siemens is used universally in science and often in electrical
Therefore, option B is correct.

Note- In order to solve this question, we must understand that there is a difference between SI unit of conductance and resistance so that applications while ohm is still used in some electronics contexts. One should not get confused in this particular question and related questions.