JEE Main · 2021 · 20 Jul 2021 · Shift 2 · Heat & Thermodynamics

Which of the following graphs represent the behaviour of an ideal gas? Symbols have their usual meaning.

(A)(see structure)
(B)(see structure)
(C)(see structure)
✓ Correct
(D)(see structure)

Answer: (C)

Solution

An ideal gas obeys

P V = n R T

, so for a fixed amount of gas the product

P V

is directly proportional to the absolute temperature with the constant of proportionality

n R

. Neither

P

nor

V

alone is fixed here, but their product is tied to

T

by that single constant, so a graph of

P V

against

T

is a rising straight line of slope

n R

passing through the origin.

JEE Main · 2021 · 20 Jul 2021 · Shift 2 · Single correct option

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