This set of four books of problems is based on a translation of a Russian collection which has been in use by students in physics at Moscow State University and the Moscow Physico-Technical In­ stitute for a number of years. Where appropriate, answers and solutions to the problems are given in the second part of eachvolume.During the course of the translation of these volumes, theauthors provided a large list of amendments and additions to their Russian text and these have all been incorporated in this English edition. Many of the additional problems are on topics which have developed during recent years.The standard of the problems is roughly equivalent to an undergraduate degree course in physics at a British university, or at an American university; it varies from the simple to the rather sophisticated. They can be used in conjunction with almost any textbook on physics at the appropriate level.