The length of DNA present in a haploid cell of man is

The diploid cell of human beings has 6.6 $\times {10}^9$ bp. The length of each base pair is 0.34 $\times {10}^{-9}\mathrm{m}$.  Hence the length of DNA  of diploid cell of man is $6.6\times {10}^9\times 0.34\times {10}^{-9}$=2.2m. In a haploid cell the length of DNA is half and is therefore 1.1m.