Explanation:

The Minimum Wages Act 1948 generally specifies minimum wage rates on a per day basis, and extends to the entire country and is revised within a period of not less than five years, however there is a provision to increase dearness allowance every two years. The norms in fixing and revision of minimum wages were first recommended by ILC, 1957.

Revision of minimum wage rates is based on a 'cost of living index' and wages can be fixed for an entire state, part of the state, class or classes and employments pertaining to these categories. The fixation of wages is based on the norms mentioned and a wage board (different for different industry).