A shaft of diameter $${20^{\matrix{ { + 0.05} \cr { - 0.15} \cr } }}\,\,mm$$ and a hole of diameter $${20^{\matrix{ { + 0.20} \cr { + 0.10} \cr } }}\,\,mm$$ when assembled would yield.

With reference to $$NC$$ machines, which of the following statements is wrong?

Determine the temperature rise necessary to induce buckling in a 1 m long circular rod of diameter 40 mm shown in the figure below. Assume the rod to be pinned at its ends and the coefficient of thermal expansion as 20 $$ \times $$ 10^-6/^oC. Assume uniform heating of the bar.

At a point in a stressed body the state of stress on two planes $$45$$⁰ apart is as shown below. Determine the two principal stresses