What is the minimum load factor for dead load as per IS 800:1984 ?
- A1·3
- B1·7Correct
- C2·3
- D2·7
Solution
Concept
Load factors in plastic design (IS 800:1984)
Step-by-step solution
1. IS 800:1984 plastic design: load factor 1.7 for dead plus live load; 1.3 for dead + live + wind/earthquake. 2. The minimum load factor to be applied to dead load is 1.7.
Explanation
In plastic design, working loads are multiplied by load factors to get collapse loads.
Why the other options are wrong
1.3 applies to combinations including wind or earthquake. 2.3 and 2.7 are not code values.
Shortcut
Plastic design: DL + LL → 1.7; DL + LL + WL → 1.3.
Common mistake
Choosing 1.3.
Correct answer: B) 1·7