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Metallurgical Engineering Material Science In Metallurgy Difficulty: Medium

A simplified energy band-diagram of an intrinsic semiconductor at thermal equilibrium (300 K) is shown. In the accompanying table, which one of the four cloumns correctly represents the listed parameters? Assume same effective mass for electrons and holes. Parameter Energy-difference Column 1 Column 2 Column 3 Column 4 Band-gap ΔE 2 ΔE 1 ΔE 2 ΔE 1 Electron affinity $$\frac{{\Delta {E_1}}}{2}$$ ΔE 2 - ΔE 1 $$\frac{{\Delta {E_2}}}{2}$$ ΔE 2 - $$\left( {\frac{{\Delta {E_1}}}{2}} \right)$$ Work function ΔE 1 + ΔE 2 ΔE 2 - $$\left( {\frac{{\Delta {E_1}}}{2}} \right)$$ ΔE 1 - $$\frac{{\Delta {E_2}}}{2}$$ ΔE 2 + $$\left( {\frac{{\Delta {E_1}}}{2}} \right)$$ Coordination number in FCC crystal structure Bainite in iron-carbon alloys has a . . . . . . . . structure. 'T'h'e' 'd'i'f'f'e'r'e'n'c'e' 'i'n' 'r'e'v'e'r's'i'b'l'e' 'p'o't'e'n't'i'a'l' 'b'e't'w'e'e'n' 'o'x'y'g'e'n' 'r'e'd'u'c't'i'o'n' 'r'e'a'c't'i'o'n' 'a'n'd' 'h'y'd'r'o'g'e'n' 'e'v'o'l'u't'i'o'n' 'r'e'a'c't'i'o'n' 'o'f' 'a'n'y' 'p'H' 'i'n' 'a'n' 'a'q'u'e'o'u's' 'e'l'e'c't'r'o'l'y't'e' 'i's' '.' '.' '.' '.' '.' '.' '.' '.' 'v'o'l't'.' '['G'i'v'e'n',' 's't'a'n'd'a'r'd' 'r'e'd'u'c't'i'o'n' 'p'o't'e'n't'i'a'l's' 'f'o'r' 'h'y'd'r'o'g'e'n' 'e'v'o'l'u't'i'o'n' 'r'e'a'c't'i'o'n',' '$'$''f'r'a'c'{'{'{'E'^' ''c'i'r'c' '}'2'{'H'^' '+' '}'}'}'{'{'{'H'_'2'}'}'}' '=' 'O'V','S'H'E'$'$' 'a'n'd' 'o'x'y'g'e'n' 'r'e'd'u'c't'i'o'n' 'r'e'a'c't'i'o'n' ':' '$'$''f'r'a'c'{'{'{'E'^' ''c'i'r'c' '}'{'O'_'2'}'}'}'{'{'4'O'H'}'}' '=' '0'.'4'V','S'H'E'.'$'$' 'A'l's'o' 'P'H' '2' '=' 'P'O' '2' '=' '1' 'a't'm']' Which of the following sulphur compounds present in coal that can not be reduced by washing of coal, is not determined directly?