MCA-109

Roll No.

Enrollment No.B.Tech (M.E. & C.E. 2nd year) (Odd Semester) 2014-2015 Subject: Strength of Material

Max. Marks: 60Subject Code: MEN-207

Time: 3 hrs Note:

1. This question paper contains two sections.

2. Attempt the sections as per instructions.3. No additional answer sheet will be supplied.

SECTION-A

Q.1. This question contains ten parts. Attempt all the parts of this question:

1 x 10 = 10 (i) The combined effect of external forces acted on a body is called( a ) stress

( b ) strain( c ) load

( d ) none of these(ii) If L and L are the length and change in length respectively, the strain is equal to( a ) L/L

( b ) L/ L( c ) L* L

( d ) none of these(iii) A cantilever is a beam whose( a ) one end is fixed and another end is free( b ) both ends are fixed( c ) both end are simply supported

( d ) all of these(iv) The amount of deflection depend upon( a ) cross- section

( b ) bending moment( c ) either (a) or (b)

( d ) both (a) and (b)(v) The ratio of lateral strain to linear strain is known as (vi) The ratio of normal stress to volumetric strain is called .modulus of elasticity.(vii) A simply supported beam of span L is carrying point load W at the midpoint, the deflection at the Centre of the beam is ..(viii) The angle of twist is.. proportional to the twisting moment.(ix) Bending moment at supports in case of simply supported beam is always.

(x) A member of structure or bar which carries an axial compressive load is called(Shaft/Strut/ Tie).SECTION-B

(Attempt any Five parts)

Q.2.Attempt all questions of the following:

2X 5.0 =10(ii) A steel bar is 900 mm long; its two ends are 40 mm and 30 mm in diameter and the length of each road is 200 mm. The middle portion of the bar is 15 mm diameter and 500 mm long. If the bar is subjected to an axial load of 15KN, find the total extension in bar.Take E=200GN/mm2

(iii) Derive the relationship between the elastic moduli, i.e. E, C & K.Q.3Attempt all questions of the following:

2X 5.0 =10(i) A copper road of 40 mm diameter is surrounded tightly by a cast-iron tube of 80 mm external diameter, the ends being firmly fastened together. When put to a compressive load of 30 KN, what load will be shared by each? Also determine the amount by which the compound bar shortens if it is 2 m long.(ii) The principal tensile stresses at a point across two perpendicular planes are 80 MN/m2 and 40 MN/m2. Find the normal, tangential and resultant stresses and its obliquity on a plane at 200 with the major principal plane.Q.4.Attempt all questions of the following:

2X 5.0 =10(i) A steel bar 4 cm by 4 cm in section, 3 m long is subjected to an axial pull of 128 KN, Taking E= 200 GN/m2 calculate the alteration in the length of the bar. Calculate also the amount of energy stored in the bar during the extension.(ii) Define strain energy or resilience. Derive the formula for strain energy in simple tension or compression.Q.5.Attempt all questions of the following:

2X 5.0 =10(i) Draw the S.F. Diagram and B.M. Diagram for a cantilever carrying load whose intensity varies uniformly from zero at the free end to w per unit run at the fixed end.

(ii) Draw the S.F diagram and B.M diagram for simply supported beam loaded as shown in fig. (b).

Q.6.Attempt all questions of the following:

2X 5.0 =10

(i) A cantilever beam 150 mm wide and 200 mm deep projects 2 m out of a wall, and is carrying a point load of 40 kN at the free end. Determine the slope and deflection of the cantilever at the free end. Take E=2.1 X 105 MN/m2.(ii) ) If a circular bar of having radius R is under maximum twisting torque, T and having length L. Derive the torsion equation for the same, which is T/ J= /RQ.7.Attempt all questions of the following:

2X 5.0 =10

(i) Calculate the safe compressive load on a hollow cast iron column (one end rigidly fixed and the other end hinged) of 150 mm external diameter, 100 mm internal diameter and 10 m length. Use Eulers formula with a foctor of safety of 5, and E=95 GN/m2.(ii) A cylindrical vessel whose ends are closed by means of rigid flange plates is made of steel plate 3mm thick. The internal length and diameter of vessel are 50 cm and 25 cm respectively. Determine the longitudinal and circumferential stresses in the cylindrical shell due to an internal pressure of 3 MN.m2. Also calculate increase in length, diameter and volume of the vessel. E= 200 GN/m2 and 1/m= 0.3Page 1 of 3