Download Feb

95AM-4
Sr. No. 2
EXAMINATION OF MARINE ENGINEER OFFICER
Function: Marine Engineering at Operational Level
APPLIED MECHANICS
India (2002)
M.E.O. Class IV
(Time allowed - 3hours)
Morning Paper
Total Marks 100
NB : (1)All Questions are Compulsary
(2)All Questions carry equal marks
(3)Neatness in handwriting and clarity in expression carries weightage
1. A spring-loaded safety valve, 80 mm diameter, is set to blow off at a pressure of 8.5
bar. The mass of the valve, spindle and spring amount to 28 kg. Find the required
percentage increase in compression of the spring so that it will blow off at 13 bar.
(Note, 1 bar = 105 N/m2 )
2. A straight steel steam pipe, 5 m long, is to be fitted between two bulkheads. When
heated to its working temperature its total free expansion would be 13.5 mm. If the
compressive stress in the pipe is to be limited to 415 MN/m2, calculate the tensile stress
to be exerted on the pipe when fitted cold. Take the value of the modulus of elasticity of
the material as 207 GN / m2
3. The angle between the jib and the vertical post of a jib crane is 42 degrees, and
between the tie and the jib the angle is 36 degrees. Find the forces in the jib and tie
when a mass of 3.822 x 103 kg is suspended from the crane head.
4. The speed of a generator is increased from 1000 to 1400 revolutions per minute in 8
seconds. Find the angular acceleration in radians per second per second and the number
of revolutions turned duirng that time.
5. A body of 200 N weight rests on a horizontal plane, the coefficient of friction between
the body and the plane is 0.25. Find the force inclined upwards at 30 degrees to the
horizontal which will just cause motion.
6. The diameters of the effort plunger and load piston of a hydraulic jack are 25 mm and
70 mm respectively. The plunger is operated by a lever, the distance from the fulcrum to
the handle is 625 mm and from fulcrum to plunger is 50 mm. Calculate the velocity ratio,
mechanical advantage and efficiency if it takes a force of 80 N on the handle to lift a load
of 5.88 kN.
7. Water rises in a capillary tube through a height h. If tube is inclined to the liquid
surface at 450, the liquid will rise in the tube of to its length equal to
(a)
h
2
(b) h
(c) 2 h
(d) 2h
Give Calculations to Justify your Answer
8. 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
Give Calculations to Justify your Answer
9. 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
Give Calculations to Justify your Answer
10. 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)
Give Calculations to Justify your Answer
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