This set of Strength of Materials Multiple Choice Questions on “Deflection”.
1. Units of deflection are _________
a) kNm
b) kN/m
c) kN
d) m
Answer: d
Clarification: The term “deflection” is defined as the transverse displacement of a point on any straight axis to the curved axis. It is expressed in metres (m).
2. Which of the following method is used to determine the slope and deflection at a point?
a) Arithmetic increase method
b) Mathematical curve setting
c) Macaulay’s method
d) Lacey’s method
Answer: c
Clarification: Macaulay’s method was devised by Mr WH Macaulay.
Advantages:
i. Gives one continuous expression for bending moment
ii. Constants of integration can be found by using end conditions
iii. By using this method, slope and deflection at any section can be determined throughout the length of the beam.
3. Deflection is denoted by _______
a) i
b) y
c) h
d) e
Answer: b
Clarification: The deflection of a point on the axis of the deflected beam is defined as the angle developed in radians with tangent at the section makes with the original axis of the beam.
4. In cantilever beams, the deflection is zero at ___________
a) Free and
b) Fixed end
c) At supports
d) Through out
Answer: b
Clarification: The deflection in cantilever beam is always zero at the fixed end and deflection in the cantilever beam at the free end is maximum.
5. Mohr’s theorem -¡¡ states?
a) Ax/EI
b) A/Ex
c) A/EI
d) Ae=Ix
Answer: a
Clarification: Mohr’s theorem -¡¡ states “the intercept taken on a vertical reference line of the tangent at any two points on an elastic line is equal to the moment of BMD between these points, about the reference line divided by flexural rigidity (EI).
6. Calculate the deflection if the slope is 0.0225 radians. Take the distance of centre of gravity of bending moment to free end as 2 metres.
a) 45mm
b) 35mm
c) 28mm
d) 49mm
Answer: a
Clarification: The deflection at any point on the elastic curve equal to Ax/EI
But, we know that A/EI is already slope equation.
So, slope × (the distance of centre of gravity of bending moment to free end = 2m).
0.0225 × 2
0.045m ~ 45 mm.
7. In simply supported beams, deflection is zero at _________
a) Mid span
b) Supports
c) Through out
d) Point of action of load
Answer: b
Clarification: The deflection is always zero at the supports and the deflection is maximum at the mid span of a symmetrically loaded simply supported beam.
8. Which of the following is not a cross drainage work?
a) Aqueduct
b) Level crossing
c) Head regulator
d) Super passage
Answer: c
Clarification: The head regulator is one of the canal regulation works. It can control the entry of silt into the canal. It can be used as a metre for measuring the discharge. It can shut out river floods.
9. Tail escape is also called as ___________
a) Outlet
b) Cross regulator
c) Weir type escape
d) Surplus escape
Answer: c
Clarification: The crest of the weir is fixed at canal FSL. When the water level rises above FSL, it is disposed of into the natural drain. Hence, the tale escape is also known as weir type escape.
10. The land where all the water comes from ___________
a) Ridge dam
b) Watershed
c) Meander
d) Groynes
Answer: b
Clarification: A watershed can be defined as an interconnected area of land which receives the water from surrounding ridge tops and transports it to a common point such as a lake or stream. All lands and waterways can be found within one watershed or another.
11. ____________ reduces storm water discharge.
a) Rain water harvesting
b) Water harvesting
c) Watershed
d) Watershed management
Answer: b
Clarification: The water harvesting is defined as the process of capturing rain where it falls. The objectives of water harvesting are 1) To provide drinking water 2) To provide irrigation water 3) To increase groundwater recharge to reduce storm water discharge.
12. Which of the following is not a soil moisture conservation method?
a) Spreading manure
b) Crop rotation
c) Recharge to ground water
d) By mulches
Answer: c
Clarification: The methods which are adopted for preserving the water in the soil from being lost are called as soil moisture conservation methods. The major part of the water is lost through evapotranspiration. The recharge to groundwater is one of the techniques in rainwater harvesting.
13. Nutrients like ca, mg, si, al, S, K are lost due to ____________
a) Soil erosion
b) Percolation
c) Water logging
d) Watershed
Answer: b
Clarification: The percolation is defined as a downward movement of water through the soil due to the force of gravity. The rapid percolation of water results in loss of plant nutrients and makes the soil acidic.
14. Warabandi has been practiced in India for more than ____________ years.
a) 130 years
b) 125 years
c) 140 years
d) 145 years
Answer: b
Clarification: Warabandi is a rotational method for allocation of the available water equally in an irrigation system. It provides continuous rotation of water generally lasts 7 days. It has been effectively practiced in India for more than 125 years.
15. Gold, Copper and lead are the examples of ______
a) Ductility
b) Creep
c) Plasticity
d) Malleability
Answer: c
Clarification: Plasticity in the property of Material by which the material can undergo permanent deformation and fails to regain its original shape on removal of load. Examples are gold, lead, etc.