Four columns of same material and same length are of rectangular cross—section of same breadth b. The depth of the cross— section and the end conditions are, however different are given as follows
Column Depth End conditions
1. 0.6 b Fixed—Fixed
2. 0.8 b Fixed—hinged
3. 1.0 b Hinged—Hinged
4. 2.6 b Fixed—Free
Which of the above columns has the maximum value of Euler buckling load?
(a) Column 1 (b) Column 2
(c) Column 3 (d) Column 4