Optimum number of effects in a multiple effect evaporator is decided by the________?

Hard pitch is used for making________?

Addition of plasticisers to polymers results in partial neutralisation of intermolecular forces of attraction between the macro-molecules thereby increasing its________?

The internal energy of an ideal gas does not change in a reversible ________ process?

Which of the following constituents of a fuel does not contribute to its calorific value on combustion?

The ability of a material to offer resistance to scratching or indentation is a measure of its________?