JNTU
JNTU B.Tech II MECHANICS OF SOLIDS Previous Question Paper (December - 2018 - R15)
Note: This question paper contains two parts A and B. Part A is compulsory which carries 25 marks. Answer all questions in Part A. Part B consists of 5 Units. Answer any one full question from each unit.
Part A
What is Poisson’s ratio and volumetric strain?
Answer
Poisson's ratio is the ratio of lateral strain to longitudinal strain within the elastic limit. Volumetric strain is the ratio of change in volume to the original volume of a body subjected to external forces.
What is difference between resilience and toughness?
Answer
Resilience is the capacity of a material to absorb energy when it is deformed elastically and release it upon unloading. Toughness is the ability of a material to absorb energy and deform plastically before fracturing; it represents the total energy absorbed up to the point of failure.
Differentiate between fixed beam and overhanging beam.
Answer
Sign in to view the complete answer paper.
What is point of contra flexure?
Answer
Sign in to view the complete answer paper.
What is neutral axis and mention its importance?
Answer
Sign in to view the complete answer paper.
Why I Section is preferred over other sections for bending?
Answer
Sign in to view the complete answer paper.
What is principal plane and principal stresses?
Answer
Sign in to view the complete answer paper.
How to find major principal stress when combined bending and torsion are present?
Answer
Sign in to view the complete answer paper.
What assumptions are made in deriving torsion equation?
Answer
Sign in to view the complete answer paper.
How volumetric strain is found in thin cylinder.
Answer
Sign in to view the complete answer paper.
Part B
A steel bar 1 m long its two ends are 45 mm and 35 mm in diameter and length of each is 250mm. The middle portion of the bar is 20 mm diameter and 450 mm long. If the bar is subjected to an axial tensile load of 15 kN. Find its total extension. Take E=200GN/m2.
Answer
Sign in to view the complete answer paper.
A copper sleeve 22 mm internal 28mm external diameter surrounds a 20 mm steel bolt. One end of sleeve being in contact with the shoulder of the bolt. The sleeve is 70 mm long. After putting a rigid washer on the other end of the sleeve, a nut is screwed on the bolt through 10 degrees. If the pitch of the thread is 3.0 mm, Find the stresses induced in the copper sleeve and steel bolt. Take Es=200GN/m2 and Ec =90GN/m2.
Answer
Sign in to view the complete answer paper.
A simply supported beam of 9 m long carries a point load of 3 KN at 3 m from left end and another point load of 4 KN at 3 m from right end and carries a UDL of 1 KN/m between the point loads. Draw S.F and BM Diagrams.
Answer
Sign in to view the complete answer paper.
An overhanging beam ABC is supported at A and B over a span of 5 m and BC over-hangs by 2.5 m. If a point load of 6 KN is placed centrally between the supports and a UDL of 2 KN/m over the overhanging length BC. Draw SF and BM Diagrams indicating salient points.
Answer
Sign in to view the complete answer paper.
A hallow circular beam has outside diameter twice inside diameter is subjected to a bending moment of 50 kN. If the allowable stress for the material is 120MN/m2, determine inside and outside diameter of the beam.
Answer
Sign in to view the complete answer paper.
A beam of channel section 120mm×60mm has uniform thickness of 16mm. Draw the diagram showing the distribution shear stress for a vertical section where shearing force is 80kN. Find the ratio between maximum and mean stresses.
Answer
Sign in to view the complete answer paper.
A rectangular block of material is subjected to a tensile stress of 120MN/m2 on one plane and a compressive stress of 60MN/m2 on a plane at right angles, together with the shear stress of 60 MN/m2 on the same planes. Find:
Magnitude and direction of the principal stresses
Answer
Sign in to view the complete answer paper.
The magnitude of the greatest shear stresses.
Answer
Sign in to view the complete answer paper.
What is maximum principal stress theory and explain why it is used for brittle materials?
Answer
Sign in to view the complete answer paper.
A mild steel shaft 100 mm diameter is subjected to a maximum torque of 18 kNm and a maximum bending moment of 10 KNm at a particular section. Find the factor of safety according to maximum shear stress theory, if the maximum elastic limit in simple tension is 2400 MN/m2.
Answer
Sign in to view the complete answer paper.
Why hallow shafts are preferred over solid shafts?
Answer
Sign in to view the complete answer paper.
A solid steel shaft is subjected to a torque running at 300 rpm developing a power of 400 kw. If the angle of twist is one degree per meter length of the shaft and shear stress is not to exceed 100 Mpa, find suitable diameter of the shaft.
Answer
Sign in to view the complete answer paper.
A cylindrical air drum is 2.5m. in diameter with plates 1cm thick the efficiencies of the longitudinal and circumferential joints are respecting 80% and 40 %. If the tensile stress in the plates is to be limited 130 MPa, find maximum safe presence.
Answer
Sign in to view the complete answer paper.