This set of Strength of Materials Multiple Choice Questions on “Deflection of Simply Supported”.
1. __________ of a beam is a measure of its resistance against deflection.
a) Strength
b) Stiffness
c) Slope
d) Maximum bending
Answer: b
Clarification: The ratio of maximum deflection of a beam to its corresponding span is termed as the stiffness of the beam. It is the measure of resistance against the deflection.
2. The maximum induced ___________ stresses should be within the safe permissible stresses to ensure strength of the beam.
a) Tensile
b) Compressive
c) Bending
d) Lateral
Answer: c
Clarification: A beam is said to be strengthy when the maximum induced bending and shear stresses are within the safe permissible stresses of the beam material.
3. Elastic line is also called as ___________
a) Deflection curve
b) Plastic curve
c) Linear curve
d) Hooke’s curve
Answer: a
Clarification: The deflection curve is defined as the line to which the longitudinal axis of a beam deflects or bends under given load. This curve is also known as elastic line or elastic axis.
4. In simply supported beams, the slope is _____________ at supports.
a) Minimum
b) Zero
c) Maximum
d) Uniform
Answer: c
Clarification: The slope at any section in the deflected beam is defined as the angle developed in radians which the tangent at the section makes with the actual axis of the proposed beam. In simply supported beams, the slope is maximum at the supports.
5. In simply supported beam deflection is maximum at ____________
a) Midspan
b) Supports
c) Point of loading
d) Through out
Answer: a
Clarification: In simply supported beams, deflection is maximum at the mid span of a symmetrically loaded beam.
6. Calculate the maximum deflection of a simply supported beam if the maximum slope at A is 0.0075 radians and the distance of centre of gravity of bending moment diagram to support A is 1.33 metres.
a) 9.975 mm
b) 9.5 mm
c) 9.25 mm
d) 9.785 mm
Answer: a
Clarification: The deflection occurs at support A = A/EI = 0.0075 radians
Maximum deflection = Ax/EI = 0.0075 × 1.33
y = 9.975 mm.
7. ____________ is the best example for accelerator (admixture).
a) Sulphonated formaldehyde
b) Calcium chloride
c) Sulphonated naphthalene
d) Polyglycolesters
Answer: b
Clarification: Calcium chloride is more widely used as an accelerator. By adding two percent (2%) of the weight of cacl2 admixture to the Portland cement the Maximum strength is attained within 1-3 days.
8. _____________ is used to reduce the time for hardening of concrete.
a) Accelerators
b) Super plasticizer
c) Retarder
d) Air entraining admixture
Answer: c
Clarification: The admixtures (retarders) are generally used to reduce the time for hardening of concrete. They are used in situations like:
i. In hot weather condition, a tendency towards false set is corrected
ii. When concrete is to be placed in difficult positions.
9. Full form of LEED ________
a) Leadership in Energy and Efficiency Development
b) Leadership in Environmental and Energy Design
c) Leadership in Energy and Environmental Design
d) Leadership in Efflorescence and Energy Demand
Answer: c
Clarification: LEED stands for Leadership in Energy and Environmental Design. The fly ash is environmentally friendly solutions that meet or exceed performance specifications fly ash contributes a lot to LEED.
10. _____ has a lower heat of hydration.
a) Quarry dust
b) Fly ash
c) Ordinary Portland cement
d) Bulk sand
Answer: b
Clarification: The process that liberates heat when water is added to cement is known as heat of hydration. The process of hydration is not instantaneous. The fly ash is possessing lower heat of hydration.
11. The factors that influence rate of hydration is _________
a) The fineness of cement
b) Temperature of cement
c) Quality of water
d) Temperature of water
Answer: a
Clarification: The products of hydration are colloidal and increase the surface area of solid paste during hydration and the water is the main ingredient which reacts chemically. The rate of hydration is mainly influenced by temperature of cement.
12. The steel suits best to reinforcement with concrete.
a) False
b) True
Answer: b
Clarification: The Steel is be used for reinforcing a concrete for following properties:
i. Steel is about 30 times stronger in compression and 300 times stronger intention compared to concrete.
ii. It develops good bond with concrete
iii. It is highly fire resistant.
13. The average crushing strength of precast concrete blocks as per CAI is __________
a) 4.5 N/mm2
b) 5 N/mm2
c) 3.5 N/mm2
d) 4 N/mm2
Answer: c
Clarification: Hollow concrete blocks are used in load bearing walls. In the manufacture of these blocks, the light height aggregates are used. The recommended size is 39 × 19 × 30 cm.
The average crushing strength of blocks Shall be 5N/mm2.
14. A simply supported beam of span as shown in the figure is subjected to a concentrated load w at its metre span and also to a uniformly distributed load equality w what is the total diffraction it its midpoint.
a) 18 Wl3 /384 EI
b) 13 Wl3/ 384 EI
c) 5 Wl3/ 384 EI
d) 18 Wl3/ 384 EI
Answer: b
Clarification: The total deflection at midpoint of a simply supported beam is
y = 5Wl3/ 384 EI + Wl3/ 48 EI
y = 13Wl3/ 384 EI.