Assertion: The use of pre-stressed concrete reduces the overall dead weight of structural elements. Reason: Pre-stressing introduces internal forces in concrete that counteract the tensile forces created by external loads, thus reducing the need for thicker sections and allowing for lighter structures.
- ABoth Assertion and Reason are correct, and Reason is the correct explanation for Assertion.Correct
- BBoth Assertion and Reason are correct, but Reason is not the correct explanation for Assertion.
- CAssertion is correct, but Reason is incorrect.
- DAssertion is incorrect, but Reason is correct.
Solution
Concept
Assertion-reason on prestressing
Step-by-step solution
1. Prestressing counteracts tensile stresses, so smaller sections are enough. 2. This reduces dead weight.
Explanation
Both statements are correct, and the reason explains the assertion.
Why the other options are wrong
Options B, C, D deny that the reason explains or is true.
Shortcut
Prestress → smaller sections.
Correct answer: A) Both Assertion and Reason are correct, and Reason is the correct explanation for Assertion.