SiO2 percentage in firebrick is about________?

Pick out the wrong statement?

All analogy equations connecting friction factor and heat transfer co-efficient apply only to ________?

Which of the following is preferred for riveting?

A gas can be liquefied by pressure alone only, when its temperature is ________ its critical temperature?

The ratio of moles of a reactant converted into the desired product to that converted into unwanted product is called________?