According to IS: 456-1978, the column or the strut is the member whose effective length is greater than A. The least lateral dimension B. 2 times the least lateral dimension C. 3 times the least lateral dimension D. 4 times the least lateral dimension

The least lateral dimension
2 times the least lateral dimension
3 times the least lateral dimension
4 times the least lateral dimension

The correct answer is: A. The least lateral dimension

A column or strut is a structural member that is primarily subjected to compression. The effective length of a column or strut is the distance between the points of contraflexure, which are the points where the bending moment is zero. The effective length is always greater than the least lateral dimension of the column or strut. This is because the column or strut is not perfectly rigid, and there will be some bending due to the applied loads. The effective length is used to calculate the buckling load of the column or strut.

The least lateral dimension is the smallest dimension of the column or strut in the plane of bending. The least lateral dimension is used to calculate the slenderness ratio of the column or strut. The slenderness ratio is a measure of the column’s or strut’s susceptibility to buckling.

The following are the options for the question:

  • A. The least lateral dimension
  • B. 2 times the least lateral dimension
  • C. 3 times the least lateral dimension
  • D. 4 times the least lateral dimension

Option A is the correct answer because the effective length of a column or strut is always greater than the least lateral dimension. Option B is incorrect because the effective length is not necessarily twice the least lateral dimension. Option C is incorrect because the effective length is not necessarily three times the least lateral dimension. Option D is incorrect because the effective length is not necessarily four times the least lateral dimension.