Structural Analysis Multiple Choice Questions on “Principle of Work and Energy”.
Ue = work done by all external forces
Ui = internal work or strain energy
Δ = final elongation of bar
Θ = final angular deflection
1. Principle of virtual work was developed by mohr.
State whether the above sentence is true or false.
a) True
b) False
Answer: b
Clarification: Principle of virtual work was developed by John Bernoulli.
2. What is the relation between work done by external loads and work done by internal loads.
a) They are unequal
b) They are equal
c) Can’t say
d) Depends upon load
Answer: b
Clarification: External and internal displacements must be related by compatibility of displacement.
3. Dummy unit load method and virtual work method are two different approaches.
State whether the above statement is true or false.
a) True
b) False
Answer: b
Clarification: They both are same methods.
4. To apply this method it is :-
a) Compulsory for external and internal forces to be in equilibrium
b) Not compulsory for external and internal forces to be in equilibrium
c) Compulsory for external and internal forces to be in equilibrium in higher loads
d) Compulsory for external and internal forces to be in equilibrium in lesser loads
Answer: a
Clarification: Since we are equating work done, it compulsory for them to be in equilibrium.
5. This method can be applied when:-
a) Elastic limit is exceeded
b) Elastic limit is not exceeded
c) Doesn’t depend upon elastic limit
d) Can’t say
Answer: b
Clarification: As after elastic limit, work done can’t be equated.
6. This method can be applied when:-
a) Supports are moving
b) Supports are not moving
c) Can be applied in both case
d) Can be applied in neither cases
Answer: b
Clarification: It is required for structure to be stable for application of this method.
7. What is the shape of load-deformation curve for a linear elastic member?
a) Straight line with constant slope
b) Straight line with varying slope
c) Curve
d) Sine wave
Answer: a
Clarification: In these cases, both are directly proportional.
8. What is the shape of load-deformation curve for a non-linear elastic member?
a) Straight line with constant slope
b) Straight line with varying slope
c) Curve
d) Circle
Answer: c
Clarification: In these cases, each one has unique relationship between load and deformation.
9. What is the relation between work done and complementary work done?
a) They are always equal
b) They are always equal
c) Can’t say
d) Depends upon loading
Answer: c
Clarification: They are equal only when Hooke’s law is applicable i.e. the material is linearly elastic.
10. Conservation of energy will be applicable only when:-
a) Static load is applied
b) Dynamic load is applied
c) Can be anything
d) Large load is applied
Answer: a
Clarification: In cases of dynamic load, acceleration may occur and some of the external work will be transferred into kinetic energy.