JEE Main 2023PhysicsThermodynamicsEasyMCQ

JEE Main 2023 — Thermodynamics Question with Solution

JEE Main 2023 (29 Jan Shift 1)

Question

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : If dQ and dW represent the heat supplied to the system and the work done on the system respectively. Then according to the first law of thermodynamics dQ=dU-dW.

Reason R : First law of thermodynamics is based on law of conservation of energy.

In the light of the above statements, choose the correct answer from the option given below :

Choose an option

Show full solutionCorrect option: C
Correct answer
CBoth A and R are correct and R is the correct explanation of A

Step-by-step explanation

The first law of thermodynamics is stated as dQ=dU-dW. Since dQ is heat supplied to the system and positive thus, dW is work done on the system, i.e., negative work.

We know that the first law of thermodynamics deals with work done, and heat energy supplied or removed from a system. Therefore, it is based on the conservation of energy. The  law states that energy cannot be created or destroyed; it can only be converted from one form to another.

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About this question

This is a previous-year question from JEE Main 2023, covering the Thermodynamics chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.