# NEET Physics Thermodynamics Questions Solved

Initial pressure and volume of a gas are P and V respectively. First it is expanded isothermally to volume 4V and then compressed adiabatically to volume V. The final pressure of gas will be [Given : -

(1) 1P

(2) 2P

(3) 4P

(4) 8P

(2) In isothermal process ${P}_{1}{V}_{1}={P}_{2}{V}_{2}$

or $PV={P}_{2}×4V$

${P}_{2}=\frac{P}{4}$

${P}_{2}{{V}_{2}}^{\gamma }={P}_{3}{{V}_{3}}^{\gamma }$
$\frac{P}{4}×{\left(4V\right)}^{1.5}={P}_{2}{V}^{1.5}$
${P}_{3}=2P$