UPSC Mechanical Engineering 2022

(a) A slider-crank mechanism with crank radius 60 mm and connecting rod length 240 mm is shown in Figure 1(a). The crank is rotating with a uniform angular speed of 10 rad/s, coun…

(a) A 20 mm diameter shaft is subjected to a torque of 80 Nm and a downward bending moment of 100 Nm at the centre. Draw the state of stress on the bottom surface of the shaft at…

(a) A thin cylinder of diameter 200 mm and length 1000 mm is subjected to an internal pressure of 10 MPa. The allowable stress of the material is 200 MPa and Young's modulus is 20…

(a) An automobile weighing 15 kN is moving at a speed of 100 km per hour. The dynamic coefficient of friction between the rubber tyre and concrete road is 0·60. When the driver ja…

(a) An HSS drill during its life can drill 150 through holes in a 10 mm thick brass plate at a drill speed of 400 rpm. Another drill of same type can make only 75 holes when the d…

(a) During turning of a steel rod of 100 mm diameter, at a speed of 600 rpm, feed of 0·32 mm/rev and 3 mm depth of cut by a tool of the following geometry : inclination angle 0°,…

Q7. (a) A firm has identified four operations, which are to be conducted in succession for an order to be processed. The tolerance and mean time of each operation are given in the…

Q8. (a) (i) Discuss the mechanism of material removal in ultrasonic machining. (10 marks) (ii) What are the different parameters affecting the material removal rate in ultrasonic…

(a) Consider the system shown in Fig. 1(a). The two chambers initially have equal volumes of 28 litres and contain air (C_p = 1·005 kJ/kg-K and C_v = 0·717 kJ/kg-K) and hydrogen (…

(a) 10 g of water at 20 °C is converted into ice at –10 °C at constant atmospheric pressure. Assuming the specific heat of liquid water to remain constant at 4·2 J/g-K and that of…

(a) (i) How do the specific work output and efficiency vary with pressure ratio in a gas turbine? (ii) Prove that the efficiency of a gas turbine corresponding to the maximum work…

(a) A single-stage impulse turbine rotor has a mean blade ring diameter of 500 mm and rotates at a speed of 10000 r.p.m. The nozzle angle is 20° and the steam leaves the nozzles w…

(a) Can alcohols be used as fuel in IC engine? Explain with advantages and disadvantages. (10 marks) (b) A water-filled reactor with a volume of 1 m³ is at 20 MPa and 360 °C, and…

(a) A four-cylinder diesel engine with swept volume of 0·98 litre is tested on a performance bed. The engine running at a speed of 2500 r.p.m. against a brake with arm of 0·3 m pr…

(a) (i) Briefly discuss HC, CO and NOₓ emission formation in SI engine. Explain the dependence of these emissions on equivalence ratio with a neat diagram. (10 marks) (ii) An IC e…

(a) A VCR cycle refrigerator driven by a 60 kW compressor has a COP of 6·0. The enthalpies of saturated liquid and saturated vapor refrigerant at condenser temperature of 35 °C ar…