# NEET Physics Thermodynamics Questions Solved

Two cylinders A and B fitted with pistons contain equal amounts of an ideal diatomic gas at 300 K. The piston of A is free to move while that of B is held fixed. The same amount of heat is given to the gas in each cylinder. If the rise in temperature of the gas in A is 30 K, then the rise in temperature of the gas in B is

(1) 30 K

(2) 18 K

(3) 50 K

(4) 42 K

(4) In both cylinders A and B the gases are diatomic (γ = 1.4). Piston A is free to move i.e. it is isobaric process. Piston B is fixed i.e. it is isochoric process. If same amount of heat ΔQ is given to both then

${\left(\Delta Q\right)}_{\text{isobaric}}={\left(\Delta Q\right)}_{\text{isochoric}}$$\mu \text{\hspace{0.17em}}{C}_{p}{\left(\Delta T\right)}_{A}=\mu \text{\hspace{0.17em}}{C}_{v}{\left(\Delta T\right)}_{B}$

${\left(\Delta T\right)}_{B}=\frac{{C}_{p}}{{C}_{v}}{\left(\Delta T\right)}_{A}=\gamma {\left(\Delta T\right)}_{A}=1.4×30=42\text{\hspace{0.17em}}K.$

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