Protective gas used in the annealing furnace for steel coil comprises of
A
95% N<sub>2</sub> + 5% H<sub>2</sub>
B
5% H<sub>2</sub> + 95% N<sub>2</sub>
C
100% CO
D
100% H<sub>2</sub>
Correct Answer: 95% N<sub>2</sub> + 5% H<sub>2</sub>