85. The rise of a parabolic arch at quarter points, is equal to

A. -3 times the rise of the crown

B.1 times the rise of the crown

C. - times the rise of the crown

D. -34 times the rise of the crown

86. A linear arch is subjected only to

A. shear force

B. thrust

C. bending moment

D. both (b) and (c)

87. An arch with three hinges, is a structure

A. statically determinate

B. statically indeterminate

C. geometrically unstable

D. structurally sound but indeterminate

88. In a three hinged arch, the shear force is usually

A. maximum at crown

B. maximum at springing

C. maximum at /quarter points

D. varies with slope.

89. In a solid arch, shear force acts

A. vertically upwards

B. along the axis of the arch

C. perpendicular to the axis of arch

D. tangentially to the arch

90. An arch may be subjected to

A. shear and axial force

B. bending moment and shear force

C. bending moment and axial force

D. thrust, shear force and bending moment.

91. A three hinged parabolic arch hinged at the crown and springings, has a horizontal span of 4.8 in and a central rise of 1 m. It carries a uniformly distributed load of 0.75 tonne per metre over half left hand span. The horizontal thrust at the support will be

A. 10.8 tonnes

B. 1.08 tonnes

C. 1.8 tonnes

D. 0.8 tonnes

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