Two castings of the same metal have the same surface area one casting is in the form of a sphere and the other is a cube. What is the ratio of the solidification time for the sphere to that of cube.

Match the following

A flywheel of moment of inertia $$9.8$$ kg m² fluctuates by $$30$$ rpm for a fluctuation in energy of $$1936$$ Jouls. The mean speed of the flywheel is (in rpm)

If $$\,\,{V_N}\,\,$$ and $$\alpha $$ are the nozzle exit velocity and nozzle angle in an impulse turbine, the optimum blade velocity is given by