4. A square beam and a circular beam have the same length, same allowable stress and the same bending moment. The ratio of weights of the square beam to the circular beam is
7. When a body is subjected to a direct tensile stress (?) in one plane, then tangential or shear stress on an oblique section of the body inclined at an angle ? to the normal of the section is
10. The change in length due to a tensile or compressive force acting on a body is given by (where P = Tensile or compressive force acting on the body, l = Original length of the body, A = Cross-sectional area of the body, and E = Young's modulus for the material of the body)
