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QJEEM24Pha151: JEE Main 2024 Physics - Class 11 JEEM24Pha151 Solution: Two different adiabatic paths for the same gas intersect two…

Two different adiabatic paths for the same gas intersect two isothermal curves as shown in P-V diagram. The relation between the ratio VaVd\frac{V_a}{V_d} and the ratio VbVc\frac{V_b}{V_c} is:

JEE Main 2024 (Online) 8th April Morning Shift Physics - Heat and Thermodynamics Question 36 English

Multiple Choice Options

  • A VaVd≠VbVc\frac{V_a}{V_d} \neq \frac{V_b}{V_c}
  • B VaVd=(VbVc)−1\frac{V_a}{V_d}=\left(\frac{V_b}{V_c}\right)^{-1}
  • C VaVd=VbVc\frac{V_a}{V_d}=\frac{V_b}{V_c}
  • D VaVd=(VbVc)2\frac{V_a}{V_d}=\left(\frac{V_b}{V_c}\right)^2

Step-by-Step Verified Solution

 (1) PaVaamp;=PbVb.... (i)PcVcamp;=PdVd.... (ii)\begin{aligned}\text { (1) } P_a V_a & =P_b V_b \quad \text{.... (i)}\\P_c V_c & =P_d V_d \quad \text{.... (ii)}\end{aligned}

 (2) PaVaγ−1amp;=PdVdγ−1.... (iii)PbVbγ−1amp;=PcVcγ−1.... (iv)\begin{aligned}\text { (2) } P_a V_a^{\gamma-1} & =P_d V_d^{\gamma-1} \quad \text{.... (iii)}\\P_b V_b^{\gamma-1} & =P_c V_c^{\gamma-1} \quad \text{.... (iv)}\end{aligned}

amp; (i) ÷ (iii) ⇒VaVaγ−1=PbVbPdVdγ−1 (v) amp; (ii) ÷ (iv) ⇒VcVcγ−1=PdVdPbVbγ−1 (vi) amp; (v) × (vi) ⇒VaVaγ−1VcVcγ−1=PbVbPdVdγ−1×PdVdPbVbγ−1amp;⇒Vaγ−2Vcγ−2=Vdγ−1Vbγ−2amp;⇒VaVd=VbVc\begin{aligned}& \text { (i) } \div \text { (iii) } \Rightarrow \frac{V_a}{V_a^{\gamma-1}}=\frac{P_b V_b}{P_d V_d{ }^{\gamma-1}} \text { (v) } \\& \text { (ii) } \div \text { (iv) } \Rightarrow \frac{V_c}{V_c^{\gamma-1}}=\frac{P_d V_d}{P_b V_b{ }^{\gamma-1}} \text { (vi) } \\& \text { (v) } \times \text { (vi) } \Rightarrow \frac{V_a}{V_a^{\gamma-1}} \frac{V_c}{V_c{ }^{\gamma-1}}=\frac{P_b V_b}{P_d V_d^{\gamma-1}} \times \frac{P_d V_d}{P_b V_b^{\gamma-1}} \\& \Rightarrow V_a^{\gamma-2} V_c{ }^{\gamma-2}=V_d^{\gamma-1} V_b{ }^{\gamma-2} \\& \Rightarrow \frac{V_a}{V_d}=\frac{V_b}{V_c}\end{aligned}

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