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 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 What is Thoria? Which is expensive & radioactive, is used in crucibles for melting high purity metals Thoria Has high fusion temperature (> 3000°C) but poor resistance to thermal shock Thoria Has high resistance to basic slags All of these Which is expensive & radioactive, is used in crucibles for melting high purity metals Thoria Has high fusion temperature (> 3000°C) but poor resistance to thermal shock Thoria Has high resistance to basic slags All of these ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C. 1670 1730 1630 1520 1670 1730 1630 1520 ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Carbon refractories Are not attacked by slags, as they are not wetted by melts Do not resist temperature fluctuations Have extremely low thermal & electrical conductivities Do not burn/oxidise, when exposed to air on heating Are not attacked by slags, as they are not wetted by melts Do not resist temperature fluctuations Have extremely low thermal & electrical conductivities Do not burn/oxidise, when exposed to air on heating ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Periclase is MgCO₃ Crystalline form of MgO ZrSO₄ Amorphous magnesite MgCO₃ Crystalline form of MgO ZrSO₄ Amorphous magnesite ANSWER DOWNLOAD EXAMIANS APP
Refractory Technology Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively. 60 and 40 80 and 20 50 and 50 20 and 80 60 and 40 80 and 20 50 and 50 20 and 80 ANSWER DOWNLOAD EXAMIANS APP