ISRO Scientist or Engineer Mechanical 2016
For the following questions answer them individually
A tubular shaft, having an inner diameter of 30 mm and an outer diameter of 40 mm, is to be used to transmit 80 kW of power. The speed ofrotation of the shaft so that the shear
stress will not exceed 50 MPa is
A cantilever beam oflength L is subjected to a concentrated load P at a distance of L/3 from the free end. The deflection at the free end is
Which of the following order of crystal structure will match with metals Iron — Copper — Zinc in that order?
A resistance spot-welding operation is performed on twopieces of 1.5 mm thick sheet steel using 12000 amps current for a duration of 0.20 second. The electrodes are 6 mm in
diameter at the contacting surfaces. Resistance is assumed to be 0.0001 ohms and the resulting weld nugget is 6 mm in diameter and 2.5 mm thick. The unit melting energy for the metal is 12 J/mm$$^3$$. What portion of heat generated was used to form the weld?
A manometer is used to measure the pressure of a gas in a tank. The fluid used has a specific gravity of 0.85 and the manometer column height is 55 cm, as shown in figure. If the local atmospheric pressure is 96 kPa, what is the absolute pressure in the tank?
A crane is used to lower weights into the sea (sea water density = 1025 kg/m$$^3$$) for an underwater construction project. What is the percentage reduction in the tension
in the rope of the crane due to a rectangular 0.4 m $$\times$$ 0.4 m $$\times$$ 3 m concrete block (density = 2300kg/m*) when it is completely immersed in water compared to the tension in
the rope when it was suspendedin air
A steady, incompressible, two-dimensional velocity field is given by,
$$\vec{V} = (u, v) = (0.5 + 0.8 x)\vec{i}+(1.5 + 0.8 y)\vec{j}$$
The number of stagnation points there in the flow field is
A piezometer and a Pitot tube are tapped into a horizontal water pipe, as shown in figure. The velocity of water at the center of the pipe is
The pressure difference between the inside and outside of a liquid droplet of diameter 'd' due to surface tension ($$\sigma$$) is given by the relation
