Solid Mechanics
2 Marks Question with Answers
UNIT -1
1. Define stress.
When an external force acts on a body, it undergoes deformation. At the same time the
body resists deformation. The magnitude of the resisting force is numerically equal to
the applied force. This internal resisting force per unit area is called stress.
Stress = Force/Area
2. Define strain
When a body is subjected to an external force, there is some change of dimension in the
body. Numerically the strain is equal to the ratio of change in length to the original length
of the body.= P/A unit is N/mm^2
Strain = Change in length/Original length
e = δL/L
3. State Hooke’s law.
It states that when a material is loaded, within its elastic limit, the stress is
directly proportional to the strain.
Stress α Strain
σαe
σ = Ee
E = σ/e unit is N/mm^2
Where,
E - Young’s modulus σ -
Stress
e - Strain
4. Define shear stress and shear strain.
The two equal and opposite force act tangentially on any cross sectional plane of the
body tending to slide one part of the body over the other part. The stress induced is called
shear stress and the corresponding strain is known as shear strain.
5. Define Poisson’s ration.
When a body is stressed, within its elastic limit, the ratio of lateral strain to the
longitudinal strain is constant for a given material.
Poisson’ ratio (µ or 1/m) = Lateral strain /Longitudinal strain
6. State the relationship between Young’s Modulus and Modulus of Rigidity.
E = 2G (1+1/m)
Where,
E - Young’s Modulus
K - Bulk Modulus
1/m - Poisson’s ratio
,7. Define strain energy
Whenever a body is strained, some amount of energy is absorbed in the body. The
energy which is absorbed in the body due to straining effect is known as strain energy.
8. What is resilience?
The total strain energy stored in the body is generally known as resilience.
9. State proof resilience
The maximum strain energy that can be stored in a material within elastic limit is
known as proof resilience.
10. Define modulus of resilience
It is the proof resilience of the material per unit volume
Modulus of resilience = Proof resilience
Volume of the body
11. Give the relationship between Bulk Modulus and Young’s Modulus.
E = 3K (1-2/m)
Where,
E - Young’s Modulus
K - Bulk Modulus
1/m - Poisson’s ratio
12. What is compound bar?
A composite bar composed of two or more different materials joined together
such that system is elongated or compressed in a single unit.
13. What you mean by thermal stresses?
If the body is allowed to expand or contract freely, with the rise or fall of temperature
no stress is developed but if free expansion is prevented the stress developed is called
temperature stress or strain.
14. Define- elastic limit
Some external force is acting on the body, the body tends to deformation. If the force is
released from the body its regain to the original position. This is called elastic limit
15. Define – Young’s modulus
The ratio of stress and strain is constant with in the elastic limit.
E = Stress
Strain
16. Define Bulk-modulus
The ratio of direct stress to volumetric strain.
K = Direct stress
Volumetric strain
, 17. Define- lateral strain
When a body is subjected to axial load P. The length of the body is increased. The axial
deformation of the length of the body is called lateral strain.
18. Define- longitudinal strain
The strain right angle to the direction of the applied load is called lateral strain.
19. What is principle of super position?
The resultant deformation of the body is equal to the algebric sum of the deformation
of the individual section. Such principle is called as principle of super position
20. Define- Rigidity modulus
The shear stress is directly proportional to shear strain.
N = Shear stress
Shear strain
UNIT –II
21. Define point of contra flexure? In which beam it occurs?
Point at which BM changes to zero is point of contra flexure. It occurs in
overhanging beam.
22. What is mean by positive or sagging BM?
BM is said to positive if moment on left side of beam is clockwise or right side of the
beam is counter clockwise.
23. What is mean by negative or hogging BM?
BM is said to negative if moment on left side of beam is counterclockwise or right side
of the beam is clockwise.
24. Define shear force and bending moment?
SF at any cross section is defined as algebraic sum of all the forces acting either side
of beam.
BM at any cross section is defined as algebraic sum of the moments of all the forces
which are placed either side from that point.
25. Derive an expression for the longitudinal stress in a thin cylinder subjected to a
uniform internal fluid pressure.
2
Force due to fluid pressure = p x /4 xd
Force due to longitudinal stress = f2 x d x t
2
p x /4 xd = f2 x d x t f2 = pd/4t
2 Marks Question with Answers
UNIT -1
1. Define stress.
When an external force acts on a body, it undergoes deformation. At the same time the
body resists deformation. The magnitude of the resisting force is numerically equal to
the applied force. This internal resisting force per unit area is called stress.
Stress = Force/Area
2. Define strain
When a body is subjected to an external force, there is some change of dimension in the
body. Numerically the strain is equal to the ratio of change in length to the original length
of the body.= P/A unit is N/mm^2
Strain = Change in length/Original length
e = δL/L
3. State Hooke’s law.
It states that when a material is loaded, within its elastic limit, the stress is
directly proportional to the strain.
Stress α Strain
σαe
σ = Ee
E = σ/e unit is N/mm^2
Where,
E - Young’s modulus σ -
Stress
e - Strain
4. Define shear stress and shear strain.
The two equal and opposite force act tangentially on any cross sectional plane of the
body tending to slide one part of the body over the other part. The stress induced is called
shear stress and the corresponding strain is known as shear strain.
5. Define Poisson’s ration.
When a body is stressed, within its elastic limit, the ratio of lateral strain to the
longitudinal strain is constant for a given material.
Poisson’ ratio (µ or 1/m) = Lateral strain /Longitudinal strain
6. State the relationship between Young’s Modulus and Modulus of Rigidity.
E = 2G (1+1/m)
Where,
E - Young’s Modulus
K - Bulk Modulus
1/m - Poisson’s ratio
,7. Define strain energy
Whenever a body is strained, some amount of energy is absorbed in the body. The
energy which is absorbed in the body due to straining effect is known as strain energy.
8. What is resilience?
The total strain energy stored in the body is generally known as resilience.
9. State proof resilience
The maximum strain energy that can be stored in a material within elastic limit is
known as proof resilience.
10. Define modulus of resilience
It is the proof resilience of the material per unit volume
Modulus of resilience = Proof resilience
Volume of the body
11. Give the relationship between Bulk Modulus and Young’s Modulus.
E = 3K (1-2/m)
Where,
E - Young’s Modulus
K - Bulk Modulus
1/m - Poisson’s ratio
12. What is compound bar?
A composite bar composed of two or more different materials joined together
such that system is elongated or compressed in a single unit.
13. What you mean by thermal stresses?
If the body is allowed to expand or contract freely, with the rise or fall of temperature
no stress is developed but if free expansion is prevented the stress developed is called
temperature stress or strain.
14. Define- elastic limit
Some external force is acting on the body, the body tends to deformation. If the force is
released from the body its regain to the original position. This is called elastic limit
15. Define – Young’s modulus
The ratio of stress and strain is constant with in the elastic limit.
E = Stress
Strain
16. Define Bulk-modulus
The ratio of direct stress to volumetric strain.
K = Direct stress
Volumetric strain
, 17. Define- lateral strain
When a body is subjected to axial load P. The length of the body is increased. The axial
deformation of the length of the body is called lateral strain.
18. Define- longitudinal strain
The strain right angle to the direction of the applied load is called lateral strain.
19. What is principle of super position?
The resultant deformation of the body is equal to the algebric sum of the deformation
of the individual section. Such principle is called as principle of super position
20. Define- Rigidity modulus
The shear stress is directly proportional to shear strain.
N = Shear stress
Shear strain
UNIT –II
21. Define point of contra flexure? In which beam it occurs?
Point at which BM changes to zero is point of contra flexure. It occurs in
overhanging beam.
22. What is mean by positive or sagging BM?
BM is said to positive if moment on left side of beam is clockwise or right side of the
beam is counter clockwise.
23. What is mean by negative or hogging BM?
BM is said to negative if moment on left side of beam is counterclockwise or right side
of the beam is clockwise.
24. Define shear force and bending moment?
SF at any cross section is defined as algebraic sum of all the forces acting either side
of beam.
BM at any cross section is defined as algebraic sum of the moments of all the forces
which are placed either side from that point.
25. Derive an expression for the longitudinal stress in a thin cylinder subjected to a
uniform internal fluid pressure.
2
Force due to fluid pressure = p x /4 xd
Force due to longitudinal stress = f2 x d x t
2
p x /4 xd = f2 x d x t f2 = pd/4t
