An R.C.C beam of 25 cm width has a clear span of 5 metres and carries a U.D.L. of 2000 kg/m inclusive of its self weight. If the lever arm of the section is 45 cm., the beam is

In a doubly-reinforced beam if c and t are stresses in concrete and tension reinforcement, d is the effective depth and n is depth of critical neutral axis n, the following relationship holds good