3. If A is the sectional area of a prestressed rectangular beam provided with a tendon prestressed by a force P through its centroidal longitudinal axis, the compressive stress in concrete, is
4. If the neutral axis of a T-beam is below the slab, the relationship between the flange width B, depth of neutral axis n, thickness of the slab ds, effective depth of the beam d, gross area of tensile steel At and the modular ratio m may be stated as
8. If Ac, Asc and A are areas of concrete, longitudinal steel and section of a R.C.C. column and m and ?c are the modular ratio and maximum stress in the configuration of concrete, the strength of column is