$$1$$ g of water of volume $$1$$ cm3 at $$100^\circ \text{C}$$ is converted into steam at the same temperature under normal atmospheric pressure $$\approx 1\times10^{5}$$ Pa. The volume of steam formed equals $$1671$$ cm3. If the specific latent heat of vaporization of water is $$2256$$ J/g, the change in internal energy is:
1. $$2423$$ J
2. $$2089$$ J
3. $$167$$ J
4. $$2256$$ J

Subtopic:  First Law of Thermodynamics |
66%
From NCERT
NEET - 2019
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A sample of $$0.1$$ g of water at $$100^{\circ}\mathrm{C}$$ and normal pressure ($$1.013 \times10^5$$ N m–2) requires $$54$$ cal of heat energy to convert it into steam at $$100^{\circ}\mathrm{C}$$. If the volume of the steam produced is $$167.1$$ cc, then the change in internal energy of the sample will be:
1. $$104.3$$ J
2. $$208.7$$ J
3. $$42.2$$ J
4. $$84.5$$ J

Subtopic:  First Law of Thermodynamics |
69%
From NCERT
NEET - 2018
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The figure below shows two paths that may be taken by gas to go from state $$A$$ to state $$C$$

In process $$AB$$, $$400~\text{J}$$ of heat is added to the system, and in process $$BC$$, $$100~\text{J}$$ of heat is added to the system. The heat absorbed by the system in the process $$AC$$ will be:
1. $$380~\text{J}$$
2. $$500~\text{J}$$
3. $$460~\text{J}$$
4. $$300~\text{J}$$

Subtopic:  First Law of Thermodynamics |
58%
From NCERT
NEET - 2015
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An ideal gas goes from state $$A$$ to state $$B$$ via three different processes as indicated in the $$(P\text-V)$$ diagram.

If $$Q_1,Q_2,Q_3$$${}_{}$ indicate the heat absorbed by the gas along the three processes and $$\Delta U_1, \Delta U_2, \Delta U_3$$ indicate the change in internal energy along the three processes respectively, then:

 1 $$Q_3>Q_2>Q_1$$ and $$\Delta U_1= \Delta U_2= \Delta U_3$$ 2 $$Q_1=Q_2=Q_3$$  and $$\Delta U_1> \Delta U_2> \Delta U_3$$ 3 $$Q_3>Q_2>Q_1$$  and $$\Delta U_1> \Delta U_2> \Delta U_3$$ 4 $$Q_1>Q_2>Q_3$$  and $$\Delta U_1= \Delta U_2= \Delta U_3$$
Subtopic:  First Law of Thermodynamics |
79%
From NCERT
AIPMT - 2012
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During an isothermal expansion, a confined ideal gas does -150 J of work against its surrounding. This implies that:

 1 300 J of heat has been added to the gas. 2 no heat is transferred because the process is isothermal. 3 150 J of heat has been added to the gas. 4 150 J of heat has been removed from the gas.

Subtopic:  First Law of Thermodynamics |
66%
From NCERT
AIPMT - 2011
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If $$\Delta U$$ and $$\Delta W$$ represent the increase in internal energy and work done by the system respectively in a thermodynamical process, which of the following is true?

 1 $$\Delta U=-\Delta W$$, in an adiabatic process 2 $$\Delta U=\Delta W$$ , in an isothermal process 3 $$\Delta U=\Delta W$$,  in an adiabatic process 4 $$\Delta U=-\Delta W$$, in an isothermal process
Subtopic:  First Law of Thermodynamics |
81%
From NCERT
AIPMT - 2010
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The internal energy change in a system that has absorbed $$2$$ kcal of heat and done $$500$$ J of work is:
1. $$8900$$ J
2. $$6400$$ J
3. $$5400$$ J
4. $$7900$$ J

Subtopic:  First Law of Thermodynamics |
78%
From NCERT
AIPMT - 2009
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One mole of an ideal gas at an initial temperature of $$T$$ K does $$6R$$ joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is $$5/3$$, the final temperature of the gas will be:
1. $$(T-2.4)$$ K
2. $$(T+4)$$ K
3. $$(T-4)$$ K
4. $$(T+2.4)$$ K

Subtopic:  First Law of Thermodynamics |
55%
From NCERT
AIPMT - 2004
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We consider a thermodynamic system. If ∆U represents the increase in its internal energy and W the work done by the system, which of the following statements is true?

 1 $$\Delta \mathrm{U}=-\mathrm{W}$$  in an isothermal process 2 $$\Delta \mathrm{U}=\mathrm{W}$$ in an isothermal process 3 $$\Delta \mathrm{U}=-\mathrm{W}$$ in an adiabatic process 4 $$\Delta \mathrm{U}=\mathrm{W}$$  in an adiabatic process
Subtopic:  First Law of Thermodynamics |
83%
From NCERT
AIPMT - 1998
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