Strength of Material Sheet 28
-
1) Question.
Assertion : Macaulay's method to determine the slope and deflection at a point in a beam is suitable for beams subjected to concentrated loads and can be extended to unifomly distributed loads.
Reason : Macaulay's method is based upon the modification of moment area method. This is applicable to a simple beam carrying a single concentrated load
Answer. -
2) Question.
Assertion : A bar tapers from a diameter of to a diameter of over its length and is subjected to a tensile
force . If extension is calculated based on treating it as a bar of average diameter, the calculated extension will be
more than the actual extension.
Reason
3) Question.Assertion : Bending moment may be defined as the algebraic sum of the moments of all forces on either side of the section.
Reason : The rate of change of bending moment is equal to shear force at the section.
Answer.4) Question.Assertion : The buckling load for a column of specified material, cross section and end conditions calculated as per Euler's formula varies inversely with the column length.
Reason : Euler's formula takes into account the end conditions in determining the effective length of column.
Answer.5) Question.Assertion : A beam of circular cross-section in comparison to rectangular section of the same material but of equal cross sectional area can resist a larger shear force.
Reason The maximum intensities of shear stress in the sections of a beam of circular cross section and of a rectangular cross section are 1.33 times and 1.5 times the average shear stress respectively.
Answer.6) Question.Assertion : I-section is preferred to rectangular section for resisting bending moment.
Reason : In I-section more than of bending moment is resisted by flanges only.
Answer.7) Question.Assertion : The maximum bending moment occurs where the shear force is either zero or changes sign.
Reason : If the shear force diagram line between the two, points is horizontal, the diagram line is inclined. But if
the diagram is inclined, the diagram is a parabola of second degree.
Answer.8) Question.Asserrtion : Strain is a fundamental behaviour of the material, while the stress is a derived concept.
Reason : Strain does not have a unit while the stress has a unit.
Answer.9) Question.Assertion : Bending moment in a beam is maximum at a section where shear force is zero.
Reason : Shear force at a section is given by the rate of change of bending moment
Answer.10) Question.Assertion : In a Mohr's circle, the vertical coordinates of the ends of any diameter are equal in magnitude and opposite in direction.
Reason : The shear stresses on two planes at right angles are equal in magnitude and tend to rotate the element in opposite directions.
Answer.11) Question.Match List I (Euler load formulae for different end restraints) with List II (conditions of end restraints) and select the correct answer using the codes given below the lists:
List I List II
A. 1. Pin-ended at both ends
B.
Answer.12) Question.A truss carries two horizontal and two vertical loads, as shown in Fig. 10.76.
The horizontal and vertical components of the reaction at will be
Answer.13) Question.Two similar round bars and are each long as shown in Fig. 10.74.
The ratio of the energies stored by the bars and ,
Answer.14) Question.A column section as indicated in Fig. 10.73 is loaded with a concentrated load at a point so as to produce maximum
bending stress due to eccentricities about XX axis and YY axis as and respectively.
If the direct stres
Answer.15) Question.Fig. 10.72 shows a retaining wall of base width and height . The sp. gravity of the material of construction is S. Further
Answer.16) Question.The 'Euler' load for a column is and crushing load is . The 'Rankine' load is equal to
Answer.17) Question.A timber beam of rectangular section is simply supported at the ends, has a
steel strip securely fixed to the top surface as shown in Fig. 10. 71.
The centroid of the ''equivalent timber b
Answer.18) Question.Match List I with List II and select the correct answer using the codes given below the lists:
List I List II
A. Partial derivative 1. Equation for
of strain energy shear force
w.r.t. a load
B. Derivative of 2. Equation for
deflection slope
C. Derivative of 3. Equation f
Answer.19) Question.Match List I with List II and select the correct answer using the codes given below the lists:
List I List II
(Beam with loading) (B.M. diagram)
Codes:
Answer.20) Question.The slope at the support of the overhanging beam shown in Fig. 10.69 is
Answer.