Assertion: Two thin blankets put together are warmer than a single blanket of double the thickness.
Reason: Thickness increases because of the air layer enclosed between the two blankets.
(A) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
(B) Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
(C) Assertion is correct but Reason is incorrect
(D) Assertion is incorrect but Reason is correct.

Hint:In winter times, the blanket, sweaters are used to keep the body in a warmer state even though the outer environment is cooler. The blanket is made of wool, it is a nonconductor of the heat and the pores in the blanket are filled with air, it is also a nonconductor of heat.

Complete step by step answer:
In Assertion, it is given that using two thin blankets keeps the body in a warmer state than the one single blanket which is doubly thick. First let us analyze the assertion. In two thin blankets there will be the space between them, and this space is filled with the air. It is known that the air is a bad conductor of heat and electricity.

Hence the heat of the body is still maintained, by not conducting it to the external environment. But in the doubly thick blanket, all the pores are filled with less air passage, hence due to the absence of air, it is not warmer than the former. Hence the assertion is correct. Air reduces the heat not thickness. So the reason is wrong.

Thus the option (C) is correct.

Note: You can think about how the air transfers heat from one body to the other. This is because of the convection mode of heat transfer. From the different states, the heat transfers through this by the movement of the molecules in the medium.