In what cases can Parliament declare control of an industry by the Union to be expedient in the public interest?
In the given context, Parliament can declare control of an industry by the Union to be expedient in the public interest when it is related to the cases specified in Entries 52 and 43. Entry 43 covers incorporation, regulation, and winding up of trading corporations including banking, insurance, and financial corporations (excluding co-operative societies), while Entry 52 refers to industries whose control by the Union is declared as expedient by Parliament by law in the public interest.