Flexibility of a structure may be defined as the displacement caused by ----------------- force and stiffness of a structure may be defined as the force required for ----------------- displacement

In flexibility method the unknown quantities are ----------------- whereas in stiffness method the unknown quantities are --------------

A single bay portal frame of height $$'h'$$ fixed at the base is subjected to a horizontal displacement $$'\delta '$$ at the top. The base moments developed is proportional to _____, where $$'{\rm I}'$$ is the moment of inertia of the cross section.

The ratio of the stiffness of a beam at the near end when the far end is hinged to the stiffness of the beam at the near end when the far end is fixed is