1. Define stress and strain.
Stress: The internal resistance per unit area developed in a body to resist deformation when
subjected to an external force.
Formula: Stress (σ) = Force (F) / Area (A)
Unit: N/m² or Pascal (Pa)
Strain: The ratio of change in dimension (length, area, or volume) to the original dimension
when a material is subjected to stress.
Formula: Strain (ε) = Change in Length (ΔL) / Original Length (L)
Unit: It is dimensionless (no unit).
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2. What is the difference between tensile and compressive stress?
Tensile stress: When the force causes elongation of a material, the stress is termed tensile
stress.
Example: A steel rod under pulling force.
Compressive stress: When the force causes shortening or compression of a material, the stress
is called compressive stress.
Example: A column under a load from above.
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3. State Hooke's Law.
Hooke's Law: Within the elastic limit, the stress applied to a material is directly proportional to
the strain produced.
Formula: σ = E × ε
Where,
σ = Stress
E = Modulus of elasticity
ε = Strain
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4. Define Young's Modulus and give its unit.
Young’s Modulus (E): It is the ratio of tensile or compressive stress to the corresponding strain
within the elastic limit.
Formula: E = Stress / Strain
Unit: N/m² or Pascal (Pa)
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5. What is Poisson’s ratio?
Poisson’s Ratio (ν): It is the ratio of lateral strain to longitudinal strain.
Formula: ν = Lateral Strain / Longitudinal Strain
Typical Range: 0.2 to 0.3 for most metals.
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6. Define the term factor of safety (FOS).
Factor of Safety (FOS): It is the ratio of ultimate strength of a material to the working or
allowable stress.
Formula: FOS = Ultimate Strength / Working Stress
Purpose: Ensures that the structure can withstand unexpected loads.
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7. What are the different types of beams?
1. Simply supported beam: Supported at both ends.
2. Cantilever beam: Fixed at one end and free at the other.
Stress: The internal resistance per unit area developed in a body to resist deformation when
subjected to an external force.
Formula: Stress (σ) = Force (F) / Area (A)
Unit: N/m² or Pascal (Pa)
Strain: The ratio of change in dimension (length, area, or volume) to the original dimension
when a material is subjected to stress.
Formula: Strain (ε) = Change in Length (ΔL) / Original Length (L)
Unit: It is dimensionless (no unit).
---
2. What is the difference between tensile and compressive stress?
Tensile stress: When the force causes elongation of a material, the stress is termed tensile
stress.
Example: A steel rod under pulling force.
Compressive stress: When the force causes shortening or compression of a material, the stress
is called compressive stress.
Example: A column under a load from above.
---
3. State Hooke's Law.
Hooke's Law: Within the elastic limit, the stress applied to a material is directly proportional to
the strain produced.
Formula: σ = E × ε
Where,
σ = Stress
E = Modulus of elasticity
ε = Strain
, ---
4. Define Young's Modulus and give its unit.
Young’s Modulus (E): It is the ratio of tensile or compressive stress to the corresponding strain
within the elastic limit.
Formula: E = Stress / Strain
Unit: N/m² or Pascal (Pa)
---
5. What is Poisson’s ratio?
Poisson’s Ratio (ν): It is the ratio of lateral strain to longitudinal strain.
Formula: ν = Lateral Strain / Longitudinal Strain
Typical Range: 0.2 to 0.3 for most metals.
---
6. Define the term factor of safety (FOS).
Factor of Safety (FOS): It is the ratio of ultimate strength of a material to the working or
allowable stress.
Formula: FOS = Ultimate Strength / Working Stress
Purpose: Ensures that the structure can withstand unexpected loads.
---
7. What are the different types of beams?
1. Simply supported beam: Supported at both ends.
2. Cantilever beam: Fixed at one end and free at the other.
