lifting power of the magnet

hello is there any book in which i can calculate the power of the lifting magnet.... electrical technology by b.l tharaja ..i check this book .....but i didnt find that articale i check on pdf form....may b this article is in this book but in some other edition please help me findinf this topic...or anyother info related to lifitng power of magnet will be highly appreciated...thanks

Some expressions for electro magnet force are derived in this article: Electromagnet - Wikipedia, the free encyclopedia