A homogeneous, prismatic, linearly elastic steel bar fixed at both the ends has a slenderness ratio (l/r) of 105, where I is the bar length and r is the radius of gyration. The coefficient of thermal expansion of steel is 12 × 10-6 /°C. Consider the effective length of the steel bar as 0.51 and neglect the self-weight of the bar.
The differential increase in temperature (rounded off to the nearest integer) at which the bar buckles is