Structural Analysis Multiple Choice Questions on “Cable Subjected to a Uniform Distributed Load”.
1. Cable is a tension member.
a) True
b) False
Answer: a
Clarification: Cable if a flexible member and hence it cannot resist bending moment. Cable cannot bear any compressive loading but it transfers the tensile loading through it. Thus, cable is a tensile member.
2. The shape of the cable is a funicular polygon.
a) True
b) False
Answer: a
Clarification: Cable when loaded takes the shape of bending moment diagram that would be formed if the same set of the load is applied on to the simply supported beam of same length and properties. Thus, the shape of the cable is a funicular polygon.
3. The shape of the cable, when loaded with uniformly distributed load throughout the span is _____
a) Linear always
b) Parabolic always
c) Trapezoidal always
d) Linear or parabolic depending upon the intensity of loading
Answer: b
Clarification: Cable when loaded takes the shape of bending moment diagram that would be formed if the same set of the load is applied on to the simply supported beam of same length and properties. Thus, the shape of cable loaded with uniformly distributed load throughout is parabolic.
4. The horizontal thrust produced at supports of cable when loaded with uniformly throughout the span is ____
a) (frac{WL^2}{32H} )
b) (frac{WL^2}{16H} )
c) (frac{WL^2}{8H} )
d) (frac{WL^2}{2H} )
Answer: c
Clarification:
∑H = 0
HA = HB = 0
∑M = 0
H = (frac{WL^2}{8H}. )
5. Minimum tension in the cable when loaded uniformly throughout the span is ____
a) (frac{WL^2}{32H} )
b) (frac{WL^2}{16H} )
c) (frac{WL^2}{8H} )
d) (frac{WL^2}{2H} )
Answer: c
Clarification:
∑H = 0
HA = HB = 0
∑M = 0
H = (frac{WL^2}{8H} )
Minimum tension in the cable equals to the horizontal thrust produced in the cable. Therefore, minimum tension in the cable is (frac{WL^2}{8H}. )