Question

Given below are two statements one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Portland cement takes 10 hours for setting and 3 day for hardening. Reason (R): Because Portland cement is cheaper than Aluminous cement. In the light of the above statements, choose the most appropriate answer from the options given below:

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• C. (A) is correct but (R) is not correct
• D. (A) is not correct but (R) is correct

Hint:

Logic Tip: Cost comparison does not explain chemical setting and hardening processes of cement.

Answer 1

The Correct Option is B

Concept:
Cement is an important construction and sculptural material used for casting, architectural structures, moulds, and monumental sculpture. Different types of cement possess different:
• Setting times
• Hardening rates
• Strength characteristics
• Costs

Step 1:
Portland cement generally requires:
• Several hours for proper setting
• Additional days for significant hardening In practical construction terminology:
• Setting refers to initial stiffening
• Hardening refers to gaining strength over time The statement that Portland cement takes around: \[ 10 \text{ hours for setting and about } 3 \text{ days for hardening} \] is broadly acceptable in this examination context. Therefore: \[ Assertion (A) is correct \]

Step 2:
Aluminous cement is generally:
• Faster setting
• More heat resistant
• More expensive Portland cement is comparatively:
• Economical
• Widely available
• Commonly used Hence, the statement that Portland cement is cheaper than aluminous cement is also: \[ Correct \]

Step 3:
Although both statements are true:
• The setting and hardening time of Portland cement depends on its chemical composition and hydration process.
• Its lower cost compared to aluminous cement does not explain the setting time. Therefore: \[ Reason does not correctly explain Assertion \]

Step 4:
Portland cement is widely used because it:
• Is economical
• Provides good strength
• Is suitable for construction and sculptural works
• Can be easily mixed with aggregates

Step 5:
Since both statements are correct but the Reason does not explain the Assertion, the correct answer is: \[ \boxed{\text{(2) Both (A) and (R) are correct but (R) is not the correct explanation of (A)}} \]