Elastic Properties – Young's modulus E used in column allowable-compression formula (units: kg/cm2)

Introduction / Context:
Column buckling and allowable compressive stresses depend on the elastic modulus E of steel. Indian steel design in older working-stress formulations expresses E in kg/cm2, and a standardized value is used for routine calculations. This question asks for that numerical value in traditional units.

Given Data / Assumptions:

• Structural steel with typical elastic modulus near 200 GPa.
• Allowable-stress column formulas require E in kg/cm2.
• 1 GPa ≈ 10^4 kg/mm2 = 10^6 kg/cm2 / 100.

Concept / Approach:

Taking E ≈ 200–205 GPa for structural steel corresponds to about 2.0–2.05 × 10^6 kg/cm2. A commonly adopted value in Indian practice is ≈ 2.04 × 10^6 kg/cm2; in tabulations this appears as 2,044,000 kg/cm2 (2044000 kg/cm2).

Step-by-Step Solution:

Verification / Alternative check:

Using 2.04 × 10^6 kg/cm2 yields column buckling predictions consistent with code examples and design aids; small variations within 200–205 GPa do not materially affect preliminary sizing.

Why Other Options Are Wrong:

2,000,000 is slightly low; 2,045,000 and 2,047,000 are close but 2,044,000 is the standard rounded figure commonly cited in traditional tables.

Common Pitfalls:

Mixing SI units (MPa, GPa) with gravitational units (kg/cm2) mid-calculation, or using inconsistent E values across checks.

Final Answer:

2044000 kg/cm2