A single bay portal frame of height h fixed at the base is subjected to a horizontal displacement of δ at the top. Assuming all members to be prismatic, the base moments developed is proportional to:
1
\(\frac{1}{{{h^2}}}\)
2
1/h
3
\(\frac{1}{{{h^3}}}\)
4
\(\frac{1}{{\sqrt 2 h}}\)