ISRO Scientist or Engineer Mechanical May 2017

A rod of length L and area of cross section A has a modulus of elasticity E and coefficient of thermal expansion $$\alpha$$ . One end of the rod is fixed and other end is free. If the temperature of the rod is increased by $$\triangle T$$, then

The entropy of a hot baked potato decreases as it cools.

During January, at a location in Rohtang, winds at $$-6^\circ C$$ can be observed. Several meters below the ground, the temperature remains at $$27^\circ C$$. A scientist claims to have devised a power cycle exploiting this situation that has a thermal efficiency of 10%. Whether the claim is true?

The side relief angle in a cutting tool signature of 10, 20, 7, 6, 8, 15, 2 is

The missing distance between A and B in the pin figure shown below is

In an ideal gas turbine cycle with intercooling, reheating and regeneration as the number of compression and expansion states are increased, which of the following statements are correct?
I. The Brayton cycle reduces to Ericsson cycle.
II. The Brayton cycle reduces to Stirling cycle.
III. The cycle efficiency becomes equal to Carnot cycle efficiency.

Calculate the dynamic head ($$P_A - P_{static}$$) when a jet of water with a velocity, v strikes a flat plate moving with a velocity, u in the same direction as jet. (Take u = 4 m/s, v = 10 m/s and $$\rho = 1000 kg/m^3$$

The method of development of a right regular prism is

A light plane flies at 720 km/hr in standard air at an altitude of 1000 m. Determine the stagnation pressure at the leading edge of the wing. Take, $$P_{air} = 9.0 \times 10^4 N/m^2$$, $$\rho = 1.1 kg/m^3$$

Below the ductile to brittle transition temperature, weld joints show