What is the principle of least time?

What is the principle of selective precipitations ?

What is the principle of separation in centrifugation?

What is the principle of an ideal machine ?

What is the principle of an electric motor?

What is the principle of Calorimetry?

How are metals used as semiconductor refined? What is the principle of the method used?

What is the principle of Liebig's method ? How will you estimate carbon and hydrogen in this method ?

What is the principle of calorimetry.

What is the principle of method of mixture ? What other name is given to it? Name the law on which this principle is based.