ISRO Scientist or Engineer Mechanical 2014
For the following questions answer them individually
Shaft AB is 3 meter long andis free at the left end and fixed torsionally at the right end. It is subjected to variable torque as shown in the figure. The intensity of the torsional loading is given by q = 2x. The internal ‘ T, as a function of x is
A cantilever beam 6 meter long as shown in figure is subjected to a linearly varying loading which has a maximum ordinate of 360 N/m at the fixed end on the right. The moment as a function of x is
Consider the beam shown in figure. The beam is simply supported at its left end A and fixed at its right end B. It carries a load that varies in intensity from zero at support A to ‘w’ at support B according to the relation $$w_x = (x/L)w$$. The reaction component at A is
A 4 meter long solid circular cylindrical shaft transmits 1600 kW at 500 rpm. The endurancelimit of the material is 210 MPa and a factor of safety of 3 is to be used with respect to fatigue failure. Use G= 77.5 GPa. The design diameter ‘D’ of the shaft in metre is
A. three bar truss to resist a service load P= 100 kN is shown in the figure. Use a load factor of 2 and consider all three members to have equal cross-sectional areas. The yield stress of the material of which the members are fabricated is 400 MPa. The area of cross section of each truss member is
A thin-walled cylinder with closed ends for which inner radius is 0.50 meter & outer radius is 0.52 meter, is subjected to internal pressure 2 MPa. The absolute maximum shearing stress on the inner surface of the cylinder shall be
A 0.75 meter aluminium bar $$25 \times 10^{-4} m^2$$ in cross-sectional area is attached to a 0.50 meter steel bar $$15 \times 10^{-4} m^2$$ in cross-sectional area, as shown in the figure. Take E (Young’s modulus) value of 200 GPa for steel & 70 GPa for aluminum. Total shortening due to an axial compressive force of 175 KN is
Member CD of the assembly shown is an aluminium bar 0.80 meter long. Cross-sectional dimension of the bar is such that, its width is three times its thickness. For functional design of the bar CD, the allowable axial stress is 70 MPa, and the total elongation is not to exceed 0.72 mm. E value for aluminium is 70 GPa. Assume the connection at C does not reduce the net area of the bar. The thickness of the bar in metre is
A solid steel shaft transmits 40kW of power at a speed of $$\frac{75}{\pi} Hz$$. The internal torque needed in the shaft is
A simply supported beam is shown in the figure below. The location of the point of maximum moment in the beam from reaction $$R_L$$ is
