A prismatic bar has a cross-section of 25 mm by 50 mm and a length of 2000 mm. Under an axial load of 100 kN, the measured elongation of the bar is 2m

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A prismatic bar has a cross-section of 25 mm by 50 mm and a length of 2000 mm. Under an axial load of 100 kN, the measured elongation of the bar is 2mm. The tensile stress and % strain in the bar are
1. 80 MPa and 0.1%
2. 0.08 GPa and 1.0%
3. 80 N/mm2 and 1%
4. 800 MPa and 0.01%
5. 8 kN/mm2 and 0.001%

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Correct Answer - Option 1 : 80 MPa and 0.1%

Concept:

Tensile stress = ${\sigma _T} = \frac{P}{A}$

where, P = Load, A = Cross-sectional area

$\% Strain = \frac{{Δ L}}{L} \times 100$

ΔL = Change in length, L = Original length

Calculation:

Given:

B = 25 mm, D = 50 mm, L = 2000 mm, P = 100 kN, ΔL = 2 mm

Tensile stress = ${\sigma _T} = \frac{P}{A} = \frac{{100 \times {{10}^3}}}{{25 \times 50}} = 80 \ MPa$

$\% Strain = \frac{{Δ L}}{L} \times 100 = \frac{2}{{2000}} \times 100 = 0.1\%$

Hence, The tensile stress and % strain in the bar is 80 MPa and 0.1 %

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