About Book:

         I feel thoroughly satisfied in presenting the twentieth Edition of this popular book in Multicolor. The present edition of this book has been thoroughly revised and a lot of useful material has been added to improve its quality and use. It also contains lot of pictures and colored diagrams for better and quick understanding as well as grasping the subject matter.

          I am highly obliged to my son Mr. N.P.S.Khurmi B.Tech (Hons) for his dedicated and untiring efforts to revise and bring out the book in its present form.

         Although every care has been taken to check mistakes and misprints, yet it is difficult to claim perfection. Any error, omission and suggestion for the improvement of this volume, brought to my notice, will be thankfully acknowledged and incorporated in the next edition.