Q. Air of mass 1 kg, initially at 300 K and 10 bar, is allowed to expand isothermally till it reaches a pressure of 1 bar. Assuming air as an ideal gas with gas constant of 0.287 kJ/kg.K, the change in entropy of air (in kJ/kg.K, round off to two decimal places) is   Ans: 0.66 Sol:

Q. During a high cycle fatigue test, a metallic specimen is subjected to cyclic loading with a mean stress of +140 MPa, and a minimum stress of −70 MPa. The R-ratio (minimum stress to maximum stress) for this cyclic loading is Sol:

Q. A solid cube of side 1 m is kept at a room temperature of 32 °C. The coefficient of linear thermal expansion of the cube material is 1x10-5 / °C and the bulk modulus is 200 GPa. If the cube is constrained all around and heated uniformly to 42 °C, then the magnitude of volumetric (mean) stress ...

Q. A cylindrical rod of diameter 10 mm and length 1.0 m is fixed at one end. The other end is twisted by an angle of 10° by applying a torque. If the maximum shear strain in the rod is px10-3, then p is equal to (round off to two decimal places). Sol:

Q. A block of mass 10 kg rests on a horizontal floor. The acceleration due to gravity is 9.81 m/s2. The coefficient of static friction between the floor and the block is 0.2. A horizontal force of 10 N is applied on the block as shown in the figure. The magnitude of force of friction (in N) on the ...

Q. The table presents the demand of a product. By simple three-months moving average method, the demand-forecast of the product for the month of September is MonthDemandJanuary450February440March460April510May520June495July475August560 (A) ...

Q. The position vector OP of point P (20, 10) is rotated anti-clockwise in X-Y plane by an angle q = 30° such that point P occupies position Q, as shown in the figure. The coordinates (x, y) of Q are Ans: (12.32, 18.66) Sol: Let Co-ordinates of Q are (x', y') and rotation about x-y ...

Q. The length, width and thickness of a steel sample are 400 mm, 40 mm and 20 mm, respectively. Its thickness needs to be uniformly reduced by 2 mm in a single pass by using horizontal slab milling. The milling cutter (diameter: 100 mm, width: 50 mm) has 20 teeth and rotates at 1200 rpm. The feed ...

Q. Which one of the following welding methods provides the highest heat flux (W/mm2)?              (A) Oxy-acetylene gas welding            (B) Tungsten inert gas welding ...

Q. In a casting process, a vertical channel through which molten metal flows downward from pouring basin to runner for reaching the mold cavity is called              (A) ...

Q. Consider an ideal vapor compression refrigeration cycle. If the throttling process is replaced by an isentropic expansion process, keeping all the other processes unchanged, which one of the following statements is true for the modified cycle? ...

Q. A slender rod of length L, diameter d ( L >> d ) and thermal conductivity k1 is joined with another rod of identical dimensions, but of thermal conductivity k2 , to form a composite cylindrical rod of length 2L . The heat transfer in radial direction and contact resistance are negligible. The ...