External wind pressure exerted on a roof is a function of__________________?
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Answer: B. slope of roof
Explanation
External wind pressure exerted on a roof depends directly on the angle and slope of the roof surface. Steeper roof slopes alter aerodynamic drag and pressure coefficients compared to flat horizontal roofs. Roof geometry dictates whether wind flow creates positive pressure or suction across the building surface. Wind loading on buildings is calculated using aerodynamic pressure coefficients defined in national standards. Roof slope determines the angle of attack for wind streams flowing across low-rise and high-rise structures. External pressures fluctuate based on building shape, height, and surrounding terrain roughness.
Structural engineers consult IS 875 to determine accurate external wind pressure coefficients for roof design. Proper wind pressure estimation prevents roof uplift failures during severe tropical cyclones and storms. Accurate roof design protects interior building contents from weather damage during extreme wind events. Option A suggests permeability is the sole factor, ignoring the critical impact of roof slope geometry. Option C includes permeability, which primarily affects internal pressures rather than external wind forces. Option D states none of the above are correct, which contradicts established wind engineering principles.
- Subject
- Engineering
- Category
- Civil Engineering
- Topic
- —
- Difficulty
- medium
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