Refractory Technology
Thermal conductivity of refractory bricks

Increases with the amount of air entrapped in pores
Is independent of its porosity and is maximum for insulating bricks
Increases with decrease in porosity
Decreases with decreases in porosity

ANSWER DOWNLOAD EXAMIANS APP

Refractory Technology
Quartz is

Transformed to crystoballite on heating above 1470°C
Stable form of silica upto 870°C
Converted to tridymite on firing between 870 to 1470°C
All of these

ANSWER DOWNLOAD EXAMIANS APP