The reciprocal of thermal conductivity is known as ______

Which of the following is not a physical classification of rocks?

The crude impure iron extracted from the ores of iron is called as ______

Which of the following statements about electric reduction furnace is not true?

Smith’s test is used to find out ________

Which of the following statements about electric precipitators is false?

Augite forms crystals of ____ shape.

Which tool is used to remove dust from blast holes in the process of blasting?