Difficulty: Easy
Correct Answer: 150 litres
Explanation:
Introduction / Context:Estimating demand is the first step in sizing water-supply systems. Per-capita water requirement (LPCD) depends on city size, service level, climate, and policy. A representative value is often used for preliminary design, refined later with category-wise breakdowns.
Given Data / Assumptions:
Concept / Approach:Commonly adopted planning figures for Indian urban areas range around 135–150 LPCD for residential and allied uses (excluding major industries). For a single best choice among rounded values, 150 LPCD is widely used for preliminary design where explicit guidance prescribes this nominal figure.
Step-by-Step Solution:
Compare options to typical norms: 150 LPCD matches standard practice.90 LPCD is low for full service levels; 250–400 LPCD reflect high-demand categories or special facilities.Select 150 litres as the representative planning value.Verification / Alternative check:Municipal planning manuals often list 135–150 LPCD; final value is tailored to local policies.
Why Other Options Are Wrong:Too low (90, 60) for urban amenities; too high (250, 400) for typical municipal residential design without special demands.
Common Pitfalls:Ignoring category-wise additions (institutional, firefighting, losses), which can alter the total system demand beyond purely domestic use.
Final Answer:150 litres
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