Rakesh Yadav

why is sky seen blue in color?

The sky is blue due to a phenomenon called Raleigh scattering. This scattering refers to the scattering of electromagnetic radiation (of which light is a form) by particles of a much smaller wavelength.

Can there be a physical quantity which has no unit and dimension? Can a quantity have a unit without dimensions?

There is no physical quantity, which has dimension but no unit.

Because if a physical quantity has a dimension then it definitely has a unit.

Is dimensionally correct equation necessarily physically correct? What about dimensionally wrong equation?

A dimensionally correct equation need not be actually correct, but a dimensionally incorrect equation is necessarily wrong.

What is order of magnitude in physics?

The order of magnitude of a physical quantity isits magnitude in powers of ten when thephysical quantity is expressed in powers of ten with one digit to the left of the decimal.

Orders of magnitude are generally used to make very approximate comparisons and reflect very large differences.

What is the difference between accurate and precise measurement?

Can two or more than two quantities have the same dimensions?

1) Two physical quantities can only be equated if they have the same dimensions.

2) Two physical quantities can only be added if they have the same dimensions.

3) The dimensions of the multiplication of two quantities is given by the multiplication of the dimensions of the two quantities.