NEET Test Series from KOTA - 10 Papers In MS WORD
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PHXI12:THERMODYNAMICS
371453
During an adiabatic expansion of 2 moles of a gas, the change in internal energy was found \(-50\;J\). The work done during the process is
1 \({\rm{Zero}}\)
2 \(100\;J\)
3 \(-50\;J\)
4 \(50\;J\)
Explanation:
For adiabatic process \(\Delta W=-\Delta U(\because \Delta Q=0)\) \( \Rightarrow \Delta W = - ( - 50) = + 50\;J\)
PHXI12:THERMODYNAMICS
371454
A monoatomic gas is suddenly compressed to (1/81) of its initial volume adiabatically. The ratio of its final pressure to the initial pressure is (given the ratio of the specific heat of the given gas to be \(5 / 3\) )
371455
The \(\mathrm{P}-\mathrm{V}\) diagram of path followed by one mole of perfect gas in a cylindrical container is shown in figure, the work done when the gas is taken from state \(A\) to state \(B\) is:
For path \(A\) to \(B \quad P V^{3 / 2}=\) constant \(=A\) then work done \(\begin{aligned}& W=\int_{V_{1}}^{V_{2}} P d V=\int_{V_{1}}^{V_{2}} \dfrac{A}{V^{3 / 2}}=A\left[\dfrac{V^{-1 / 2}}{-1 / 2}\right]_{V_{1}}^{V_{2}} \\& =-2 A\left[V^{-1 / 2}\right]_{V_{1}}^{V_{2}}=-2 A 2 P_{1} V_{1}\left[1-\dfrac{\sqrt{V_{1}}}{\sqrt{V_{2}}}\right] \\& =2 A\left[\dfrac{1}{\sqrt{V_{1}}}-\dfrac{1}{\sqrt{V_{2}}}\right] \\& \Rightarrow 2 P_{1} V_{1}^{3 / 2}\left[\dfrac{\sqrt{V_{2}}-\sqrt{V_{1}}}{\sqrt{V_{1} V_{2}}}\right]=2 P_{1} V_{1}\left[1-\dfrac{\sqrt{V_{1}}}{\sqrt{V_{2}}}\right] \\& {\left[\because P_{1} V_{1}^{3 / 2}=\text { constant }\right] .}\end{aligned}\)
PHXI12:THERMODYNAMICS
371456
Assertion : The adiabatic curves intersect each other at a certain point. Reason : Rapid changes of gases can be treated as adiabatic changes
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Adiabatic curves never intersect each other as they are always parallel. Rapid processes are always adiabatic as there is no time for exchange of heat. So option (4) is correct.
371453
During an adiabatic expansion of 2 moles of a gas, the change in internal energy was found \(-50\;J\). The work done during the process is
1 \({\rm{Zero}}\)
2 \(100\;J\)
3 \(-50\;J\)
4 \(50\;J\)
Explanation:
For adiabatic process \(\Delta W=-\Delta U(\because \Delta Q=0)\) \( \Rightarrow \Delta W = - ( - 50) = + 50\;J\)
PHXI12:THERMODYNAMICS
371454
A monoatomic gas is suddenly compressed to (1/81) of its initial volume adiabatically. The ratio of its final pressure to the initial pressure is (given the ratio of the specific heat of the given gas to be \(5 / 3\) )
371455
The \(\mathrm{P}-\mathrm{V}\) diagram of path followed by one mole of perfect gas in a cylindrical container is shown in figure, the work done when the gas is taken from state \(A\) to state \(B\) is:
For path \(A\) to \(B \quad P V^{3 / 2}=\) constant \(=A\) then work done \(\begin{aligned}& W=\int_{V_{1}}^{V_{2}} P d V=\int_{V_{1}}^{V_{2}} \dfrac{A}{V^{3 / 2}}=A\left[\dfrac{V^{-1 / 2}}{-1 / 2}\right]_{V_{1}}^{V_{2}} \\& =-2 A\left[V^{-1 / 2}\right]_{V_{1}}^{V_{2}}=-2 A 2 P_{1} V_{1}\left[1-\dfrac{\sqrt{V_{1}}}{\sqrt{V_{2}}}\right] \\& =2 A\left[\dfrac{1}{\sqrt{V_{1}}}-\dfrac{1}{\sqrt{V_{2}}}\right] \\& \Rightarrow 2 P_{1} V_{1}^{3 / 2}\left[\dfrac{\sqrt{V_{2}}-\sqrt{V_{1}}}{\sqrt{V_{1} V_{2}}}\right]=2 P_{1} V_{1}\left[1-\dfrac{\sqrt{V_{1}}}{\sqrt{V_{2}}}\right] \\& {\left[\because P_{1} V_{1}^{3 / 2}=\text { constant }\right] .}\end{aligned}\)
PHXI12:THERMODYNAMICS
371456
Assertion : The adiabatic curves intersect each other at a certain point. Reason : Rapid changes of gases can be treated as adiabatic changes
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Adiabatic curves never intersect each other as they are always parallel. Rapid processes are always adiabatic as there is no time for exchange of heat. So option (4) is correct.
371453
During an adiabatic expansion of 2 moles of a gas, the change in internal energy was found \(-50\;J\). The work done during the process is
1 \({\rm{Zero}}\)
2 \(100\;J\)
3 \(-50\;J\)
4 \(50\;J\)
Explanation:
For adiabatic process \(\Delta W=-\Delta U(\because \Delta Q=0)\) \( \Rightarrow \Delta W = - ( - 50) = + 50\;J\)
PHXI12:THERMODYNAMICS
371454
A monoatomic gas is suddenly compressed to (1/81) of its initial volume adiabatically. The ratio of its final pressure to the initial pressure is (given the ratio of the specific heat of the given gas to be \(5 / 3\) )
371455
The \(\mathrm{P}-\mathrm{V}\) diagram of path followed by one mole of perfect gas in a cylindrical container is shown in figure, the work done when the gas is taken from state \(A\) to state \(B\) is:
For path \(A\) to \(B \quad P V^{3 / 2}=\) constant \(=A\) then work done \(\begin{aligned}& W=\int_{V_{1}}^{V_{2}} P d V=\int_{V_{1}}^{V_{2}} \dfrac{A}{V^{3 / 2}}=A\left[\dfrac{V^{-1 / 2}}{-1 / 2}\right]_{V_{1}}^{V_{2}} \\& =-2 A\left[V^{-1 / 2}\right]_{V_{1}}^{V_{2}}=-2 A 2 P_{1} V_{1}\left[1-\dfrac{\sqrt{V_{1}}}{\sqrt{V_{2}}}\right] \\& =2 A\left[\dfrac{1}{\sqrt{V_{1}}}-\dfrac{1}{\sqrt{V_{2}}}\right] \\& \Rightarrow 2 P_{1} V_{1}^{3 / 2}\left[\dfrac{\sqrt{V_{2}}-\sqrt{V_{1}}}{\sqrt{V_{1} V_{2}}}\right]=2 P_{1} V_{1}\left[1-\dfrac{\sqrt{V_{1}}}{\sqrt{V_{2}}}\right] \\& {\left[\because P_{1} V_{1}^{3 / 2}=\text { constant }\right] .}\end{aligned}\)
PHXI12:THERMODYNAMICS
371456
Assertion : The adiabatic curves intersect each other at a certain point. Reason : Rapid changes of gases can be treated as adiabatic changes
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Adiabatic curves never intersect each other as they are always parallel. Rapid processes are always adiabatic as there is no time for exchange of heat. So option (4) is correct.
NEET Test Series from KOTA - 10 Papers In MS WORD
WhatsApp Here
PHXI12:THERMODYNAMICS
371453
During an adiabatic expansion of 2 moles of a gas, the change in internal energy was found \(-50\;J\). The work done during the process is
1 \({\rm{Zero}}\)
2 \(100\;J\)
3 \(-50\;J\)
4 \(50\;J\)
Explanation:
For adiabatic process \(\Delta W=-\Delta U(\because \Delta Q=0)\) \( \Rightarrow \Delta W = - ( - 50) = + 50\;J\)
PHXI12:THERMODYNAMICS
371454
A monoatomic gas is suddenly compressed to (1/81) of its initial volume adiabatically. The ratio of its final pressure to the initial pressure is (given the ratio of the specific heat of the given gas to be \(5 / 3\) )
371455
The \(\mathrm{P}-\mathrm{V}\) diagram of path followed by one mole of perfect gas in a cylindrical container is shown in figure, the work done when the gas is taken from state \(A\) to state \(B\) is:
For path \(A\) to \(B \quad P V^{3 / 2}=\) constant \(=A\) then work done \(\begin{aligned}& W=\int_{V_{1}}^{V_{2}} P d V=\int_{V_{1}}^{V_{2}} \dfrac{A}{V^{3 / 2}}=A\left[\dfrac{V^{-1 / 2}}{-1 / 2}\right]_{V_{1}}^{V_{2}} \\& =-2 A\left[V^{-1 / 2}\right]_{V_{1}}^{V_{2}}=-2 A 2 P_{1} V_{1}\left[1-\dfrac{\sqrt{V_{1}}}{\sqrt{V_{2}}}\right] \\& =2 A\left[\dfrac{1}{\sqrt{V_{1}}}-\dfrac{1}{\sqrt{V_{2}}}\right] \\& \Rightarrow 2 P_{1} V_{1}^{3 / 2}\left[\dfrac{\sqrt{V_{2}}-\sqrt{V_{1}}}{\sqrt{V_{1} V_{2}}}\right]=2 P_{1} V_{1}\left[1-\dfrac{\sqrt{V_{1}}}{\sqrt{V_{2}}}\right] \\& {\left[\because P_{1} V_{1}^{3 / 2}=\text { constant }\right] .}\end{aligned}\)
PHXI12:THERMODYNAMICS
371456
Assertion : The adiabatic curves intersect each other at a certain point. Reason : Rapid changes of gases can be treated as adiabatic changes
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Adiabatic curves never intersect each other as they are always parallel. Rapid processes are always adiabatic as there is no time for exchange of heat. So option (4) is correct.
