In steel and iron works, dimensions excepting cross-section and thickness of plate shall be measured to nearest _____ m except for reinforcement in reinforced concrete works.
- A0.001Correct
- B0.003
- C0.005
- D0.002
Solution
Concept
In steel and iron work, lengths are measured to the nearest 0.001 m (1 mm). Reinforcement in RCC is measured by its own rule.
Step-by-step solution
1. Steel members are costly, so length must be measured accurately. 2. The measurement rules (IS 1200 / CPWD style) give dimensions of steel work to the nearest 1 mm. 3. 1 mm = 0.001 m. 4. Reinforcement in RCC is measured by its own separate rule, which is why it is excluded. 5. So the answer is 0.001 m.
Explanation
Steel is costly, so small length errors cause big cost errors. That is why steel work dimensions are taken to the nearest 1 mm (0.001 m). Reinforcement bars in RCC follow their own measurement rule.
Why the other options are wrong
Options B, C and D (0.003, 0.005, 0.002 m) are not standard rounding steps. Measurement rules round to 1 mm or 1 cm, not to 2, 3 or 5 mm.
Shortcut
Steel work is measured to 1 mm, which is 0.001 m.
Common mistake
Students mix this up with the 0.01 m rule used for ordinary works like masonry and earthwork.
Correct answer: A) 0.001