101. In a lifting machine with efficiency 60%, an effort of 200 N is required to raise a load of 6 kN. The velocity ratio of the machine is
a) 30
b) 50
c) 60
d) 80
Ans: b
102. Free body diagram is an
a) isolated joint with only body forces acting on it
b) isolated joint with internal forces acting on it
c) isolated joint with all the forces, internal as well as external, acting on it
d) none of the above
Ans: c
103. A system of copianar forces acting on a rigid body can be reduced to
a) one force only
b) one couple only
c) one force and one couple only
d) none of the above
Ans: c
104. A system of copianar forces is in equilibrium when
a) force polygon closes
b) funicular polygon closes
c) both force polygon” and funicular polygon close
d) all the forces are concurrent
Ans: c
105. Force polygon method is applicable for
a) any copianar force system
b) a system of parallel forces only
c) concurrent copianar force system
d) non-concurrent copianar force system
Ans: c
106. The force polygon representing a set of forces in equilibrium is a
a) triangle
b) open polygon
c) closed polygon
d) parallelogram
Ans: c
107. The diagram showing the point of application and line of action of forces in their plane is called
a) vector diagram
b) space diagram
c) force diagram
d) funicular diagram
Ans: b
108. If two forces are in equilibrium, then the forces must
i) be equal in magnitude
ii) be opposite in sense
iii) act along the same line
The correct answer is
a) (i) and (ii)
b) (i) and (iii)
c) only (i)
d) (i), (ii) and (iii)
Ans: d
109. The graphical method of determining the forces in the members of a truss is based on
a) method of joint
b) method of section
c) either method
d) none of the two methods
Ans: a
110. The bending moment in an arch is proportional to
a) vertical ordinate of funicular polygon
b) vertical ordinate of the arch
c) intercept between the arch axis and the funicular polygon
d) none of these
Ans: c
111. The member forces in a statically in determinate truss
a) can be obtained by graphic statics
b) cannot be obtained by graphic statics
c) may be obtained by graphic statics
d) can be obtained by graphic statics by trial and error
Ans: b
112. An ordinate in a funicular polygon represents
a) shear force
b) resultant force
c) bending moment
d) equilibrium
Ans: c
113. The pole distance is measured in
a) distance scale
b) force scale
c) mass scale
d) time scale
Ans: b
114. The number of funicular polygons which can be drawn to pass through two specified points in the space diagram are
a) zero
b) 1
c) 2
d) infinity
Ans: d
115. A funicular polygon cannot be made to pass through
a) one specified point
b) two specified points
c) three specified points
d) more than three specified points
Ans: d
116. If the given forces P,, P2, P3 and P4 are such that the force polygon does not close, then the system will
a) be in equilibrium
b) always reduce to a resultant force
c) always reduce to a couple
d) both (a) and (c)
Ans: b
117. The condition of equilibrium for any system of forces in a plane is
a) that polygon of forces must close
b) that resultant couple must be zero
c) both (a) and (b)
d) none of the above
Ans: c
118. In which of the following trusses, the method of substitution is required for determining the forces in all the members of the truss by graphic statics ?
a) howe truss
b) king post truss
c) fink truss
d) warren truss
Ans: c
119. For a non-concurrent force system to be in equilibrium
a) only the closure of force polygon is sufficient
b) only the closure of funicular polygon is sufficient
c) both force polygon and funicular polygon must close
d) none of the above
Ans: c
120. If a set of given forces are such that their free vectors build a closed polygon, then
a) the resultant force and resultant couple are always zero
b) the resultant force is zero but resultant couple is not zero
c) the resultant force is zero but resultant couple may not be zero
d) the resultant force and resultant couple both may not be zero
Ans: c