Question

Which of the following quantity is Dimensionless

(a) Resistivity (b) Refractive index (c) Electric charge. (d) None​

Answer 1

Explanation:

dimensional analysis, a dimensionless quantity is a quantity to which no physical dimension is assigned, also known as a bare, pure, or scalar quantity or a quantity of dimension one, with a corresponding unit of measurement in the SI of the unit one (or 1), which is not explicitly shown.

Answer 2

(b).Refractive index is dimensionless because it to differentiate a speed of a medium medium or medium vacuum...

resistivity dimension is ohm -meter ..

electric charge q= it .. dimension is ampere .time