1) $i^{2}+i^{3}+.......+i^{4000}$= A) 1 B) 0 C) i D) -i Answer: Option DExplanation:$\because$ $i^{n}+i^{n+1}+i^{n+2}+i^{n+3}=0,\forall n \in Integer$ So, $i^{2}+i^{3}+i^{4}+.........+i^{4000}$ = $-i+[i+i^{2}+i^{3}+.....+i^{4000}]$=-i
