95AM-4 Sr. No. 4 EXAMINATION OF MARINE ENGINEER OFFICER Function: Marine Engineering at Operational Level APPLIED MECHANICS CLASS IV INDIA (2001) (Time allowed - 3 hours) Morning Paper Total Marks 100 N.B. - (1) All questions are compulsory. (2) All questions carry equal marks. (3) Neatness in handwriting and clarity in expression carries weightage 1. Water rises in a capillary tube through a height h. If tube is inclined to the liquid surface at 45 0, the liquid will rise in the tube of to its length equal to A. h 2 B. h C. 2 h D. 2h 2. Two balls of equal masses are thrown upwards along the same vertical direction at an interval of 2 seconds. with the same initial velocity of 39.2 m/sec. Then the balls collide at a height of A. 117.6 m B. 73.5 m C. 196.0 m D. 44.1 m 3. The potential energy of a particle executing S. H. M. varies sinusoidally. lf the frequency of oscillation of the particle is n, that of potential energy is A. n/2 B. n/2 C. n D. 2n 4. Two equal masses each equal to m are attached to a spring of force constant K. Both of them are pressed together and released. They oscillate on a frictionless surface. What is the time period of oscillations. A. (m/k) B. 2 (m/k) C. 2 (m/k) D. (m/2k) 5. A person throws balls into air one after the other at an interval of one second. The next ball is thrown when the velocity of the earlier is zero.To what height the ball rise ? Take g = 10ms-2 A. 5m B. 10 m C. 20m D. 40m The pressure applied from all directions on a cube is P. How much its temperature should be raised to maintain the original volume ? The volume elasticity of the cube is and the co-efficient of volume expansion is P A. P B. P C. D. P 7. Steel bar 360mm long, 28mm diameter, is turned down to 20mm diameter for one-third of its length. It is heated 36O C above room temperature clamped at both ends and then allowed to cool to room temperature. If the distance between the clamps is unchanged find the maximum stress in the bar. = 12.5 10-6/OC; E = 200 GN/m2. 8. What is an "ideal machine"? Why ideal machine is a rare phenomenon? In an experiment of a weight lifting machine, with velocity ratio as 18, the values of effort required to lift various loads wore as given in the table below Load (W) in 250 500 750 1000 1500 2500 N Effort (P) in 42.5 62.5 82.5 105 142.5 220 N Plot the graph showing the relation between effort and load, and determine the law of the machine. Find the effort required and efficiency of the machine, when the load is 2KN. Also find the maximum efficiency, this machine can attain. 9. (a) A pump driven by a 7.5kW motor transfers 80W cu. m. of sea water with density 1025kg/m3 from one tank to another. The effective height to which the water is transferred is 6m. If the overall efficiency of the installation is 80%, how long does it take to transfer the water. (b) A crane driven by a hydraulic motor is lifting a load of mass 2 tonnes, at uniform velocity. During this operation, the motor uses, 500 liters of oil per minute, at a pressure of 4 MN/ms. If the efficiency of the motor is 85% and the efficiency of the lifting system is 80 determine the velocity at which the load is being lifted. 10. A feed water regulator has an open topped wrought iron pot to act as a float, the external dimensions being 25cm diameter and 45cm deep, and it is 3mm thick. When the pot is full of water it is required to float in the heater at a draught of 18cm. If the fulcrum is 45cm from the centre line of the pot, find what counter balance weight is required at the other end of the lever at 60cm from the fulcrum to create a state of equilibrium. Note: - Specific gravity of wrought iron = 7.78. ----------------------X----------------------- 95AM-4 Sr. No. 4 EXAMINATION OF MARINE ENGINEER OFFICER Function: Marine Engineering at Operational Level APPLIED MECHANICS CLASS IV (Time allowed - 3 hours) Morning Paper INDIA (2001) Total Marks 100 N.B. - (1) All questions are compulsory. (2) All questions carry equal marks. (3) Neatness in handwriting and clarity in expression carries weightage Answers Answer for Question No. 1 Correct Answer : C Answer for Question No. 2 Correct Answer : B Answer for Question No. 3 Correct Answer : D Answer for Question No. 4 Correct Answer : C Answer for Question No. 5 Correct Answer : A Answer for Question No. 6 Correct Answer : A Answer for Question No.7 133.64 MN/m2 Answer for Question No. 8 P = 0.08 W + 22.5 182.5 N Answer for Question No. 9 22.345 1.55 m/s Answer for Question No. 10 16 kg 60.9% 69.4 %