Concept:Quantities that are dimensionally independent are dimensionless, meaning they have no base units.
Explanation:Dielectric constant is a ratio of two permittivities, so it has no dimensions.
Refractive index is a ratio of two speeds, hence it is dimensionless.
Efficiency is the ratio of useful work output to total work input, so it has no dimensions.
Density, however, has the dimension
ML−3, so it is not dimensionally independent.
Thus, the dimensionally independent quantities are II, III and IV.
Answer:B. II, III and IV