Non-ferrous metals and hard steels do not exhibit a definite yield point, when pulled in the testing machine and hence for these cases, a better measure of their elastic properties is defined by the ________ stress?

Tolerable limit of nitrogen oxides in air is ________ ppm?

Which of the following terminology is used for the temperature at which new grains are formed in a metal?

The calorific value of natural gas is about ________ kcal/Nm3?

A good quality coal should have ________?

Water gas constitutes mainly of ________?