Engineering Questions with Answers - Multiple Choice Questions
MCQs on Introduction to Shear Stress
1 - Question
At ________ the shearing stress in a beam are maximum.
a) Extreme fibres
b) Modulus of section
c) Neutral axis
d) Along the cross-sectional area
View Answer
Answer: c
Explanation: Shearing stress in a beam is maximum at the neutral axis. Shearing stress is defined as the resistance offered by the internal stress to the shear force.
Explanation: Shearing stress in a beam is maximum at the neutral axis. Shearing stress is defined as the resistance offered by the internal stress to the shear force.
2 - Question
Determine the shear stress at the level of neutral axis, if a beam has a triangle cross section having base “b” and altitude “h”. Let the shear force be subjected is F.
a) 3F/8bh
b) 4F/3bh
c) 8F/3bh
d) 3F/6bh
View Answer
Answer: c
Explanation: For a triangular section subjected to shear force the shear stress in neutral axis is
Shear stress at NA = 4/3 [Average shear stress].
= 4/3 [F/0.5 bh] = 8F / 3bh.
Explanation: For a triangular section subjected to shear force the shear stress in neutral axis is
Shear stress at NA = 4/3 [Average shear stress].
= 4/3 [F/0.5 bh] = 8F / 3bh.
3 - Question
The maximum shear stress is ______ times the average shear stress [For rectangular beams].
a) 2.5
b) 3
c) 1.2
d) 1.5
View Answer
Answer: d
Explanation: The maximum shear stress occurs at neutral axis. Then y = 0.
Max shear stress = 3F/2bd = 3/2 [F/bd].
= 1.5 Average shear stress.
4 - Question
Shear stress in a beam is zero at ______
a) Neutral axis
b) Extreme fibres
c) Cross section
d) Junctions
View Answer
Answer: b
Explanation: The resistance offered by the internal stress to shear is known as shearing stress. Shearing stress is zero at extreme fibres of the beam. The bending stresses are maximum at extreme fibres of the beam cross section.
Explanation: The resistance offered by the internal stress to shear is known as shearing stress. Shearing stress is zero at extreme fibres of the beam. The bending stresses are maximum at extreme fibres of the beam cross section.
5 - Question
Shear stress distribution over rectangular section will be _________
a) parabolic
b) elliptical
c) triangular
d) trapezoidal
View Answer
Answer: a
Explanation:
Maximum shear stress is 1.5 times that of average shear stress.
The shear stress distribution is parabolic.
6 - Question
A round Steel rod of 100 mm diameter is bent into an arc of radius 100m. What is the maximum stress in the rod? Take E = 2×105 N/mm2.
a) 150 N/mm2
b) 200 N/mm2
c) 100 N/mm2
d) 300 N/mm2
View Answer
Answer: c
Explanation: D = 100m
y = 50 mm
R = 10 × 103mm
By equation of flexure; E/R = f/y
f=E/R ×y
= 2×105/ 100 × 103× 50
= 100 N/mm2.
7 - Question
For circular section, the maximum shear stress is equal to ____________ times of average shear stress.
a) 2/3
b) 3/2
c) 4/3
d) 3/4
View Answer
Answer: c
Explanation: Maximum shear stress occurs at neutral axis & y = 0.
Max. Shear stress = 4/3 [ F/A ].
F/A is average shear stress.
The maximum shear stress distribution is 33% more than average shear stress.
8 - Question
A steel beam is 200 mm wide and 300 mm deep. The beam is simply supported and carries a concentrated load w. If the maximum stress are 2 N/mm2. What will be the corresponding load?
a) 50 kN
b) 80 kN
c) 40 kN
d) 85 kN
View Answer
Answer: b
Explanation: For a rectangular cross section
Max. Shear stress = 3/2 [F/A ] 2 = 3/2 [w/200 × 300].
w = 80 kN.
9 - Question
Maximum shear stress in thin cylindrical shell be ___________
a) pr/2t
b) pr/3t
c) pr/4t
d) pr/ 5t
View Answer
Answer: c
Explanation: Hoop stress P(h) = pr/t
Longitudinal stress P(l) = pr/2t
Thus, hoop stress is twice the longitudinal stress
Max. Shear stress = P(h) – P(l) / 2
= pr/4t.
Explanation: Hoop stress P(h) = pr/t
Longitudinal stress P(l) = pr/2t
Thus, hoop stress is twice the longitudinal stress
Max. Shear stress = P(h) – P(l) / 2
= pr/4t.
10 - Question
Circumferential stress is same as of _________
a) Hoop stress
b) Longitudinal stress
c) Transverse stress
d) Phreatic stress
View Answer
Answer: a
Explanation: In a thin cylindrical shell of internal radius r thickness t when subjected to internal fluid pressure P, the stress developed in the internal walls can be termed as circumferential stress or hoop stress.
P(h) = pr/t.