3. If p1 and p2 are mutually perpendicular principal stresses acting on a soil mass, the normal stress on any plane inclined at angle ?° to the principal plane carrying the principal stress p1, is :
6. If permissible compressive stress in concrete is 50 kg/cm2, tensile stress in steel is 1400 kg/cm2 and modular ratio is 18, the depth d of the beam, is
8. P is the prestressed force applied to tendon of a rectangular prestressed beam whose area of cross section is A and sectional modulus is Z. The minimum stress f on the beam subjected to a maximum bending moment M is
9. The section of a reinforced beam where most distant concrete fibre in compression and tension in steel attains permissible stressess simultaneously, is called
