Question

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Thermal conductivity of foods generally increases with increase in moisture content.
Reason (R): Water has higher thermal conductivity compared to air and fat.
Choose the correct answer from the options 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:

More water → better heat conduction. Air reduces conductivity.

Answer 1

The Correct Option is A

Concept: Thermal conductivity is a measure of a material’s ability to conduct heat. In food materials, it depends strongly on composition, especially moisture content.

Step 1: Understanding thermal conductivity in foods.
Food is a heterogeneous mixture of:
• Water
• Air
• Fat
• Solids Each component has different thermal conductivity.

Step 2: Comparing conductivities.

• Water has relatively high thermal conductivity
• Air has very low thermal conductivity
• Fat has lower conductivity than water

Step 3: Effect of moisture content.
As moisture content increases:
• Proportion of water increases
• Air spaces decrease
• Overall heat conduction improves Thus, thermal conductivity increases.

Step 4: Evaluating Assertion (A).
Correct, since more moisture leads to better heat conduction.

Step 5: Evaluating Reason (R).
Correct, because water conducts heat better than air and fat.

Step 6: Linking both.
Reason directly explains why increasing moisture increases conductivity. Final Conclusion:
Both (A) and (R) are correct and (R) explains (A). Hence, option (1).