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