Question

One of the following dimensional quantities which one qualifies to be called dimensional constant?

• A. Acceleration due to gravity
• B. surface tension of water
• C. weight of standard kilogram mass
• D. The velocity of light is vaccum

Answer 1

Answer: (D)

The velocity of light is vaccum

Dimensonal constants are those constants while have both fixed magnitude and dimension.

$\Rightarrow$1) acceleration due gravity

$\Rightarrow$ Not a Dimensional constant because if planet changes magnitude.

Similarly the magnitude of surface tension and weight is not tired.

So Speed of light is best if has both fixed dimension and magnitude over all universe.

Answer is speed of light.