The economic depth of a web plate 'd' in the design of a plate girder (in working stress method) is given by which of the following expressions? (where 'M' is the maximum bending moment, 'σbc' is the permissible bending strength, and 'k' is a constant)

The strength and size specification of a butt weld is primary specified by its:

As per IS 800, the maximum bending moment for the design of purlins can be taken as (where W is the total distributed load including wind load on purlins and L is the effective span/centre distance of supports):