If a gas changes volume from 2 litres to 10 litres at a constant temperature of 300K, then the change in its internal energy will be:

1. 12 J 2. 24 J
3. 36 J 4. 0 J

Subtopic:  Molar Specific Heat |
 85%
From NCERT
AIPMT - 1998
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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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An ideal gas heat engine operates in a Carnot cycle between 227ºC and 127ºC. It absorbs 6 × 104 cals of heat at higher temperatures. The amount of heat converted to work will be?
1. 4.8 × 104 cals
2. 2.4 × 104 cals
3. 1.2 × 104 cals
4. 6 × 104 cals

Subtopic:  Carnot Engine |
 73%
From NCERT
AIPMT - 2005
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Which one of the following processes is reversible?

1.  Transfer of heat by radiation
2. Transfer of heat by conduction
3. Isothermal compression
4. Electrical heating of a nichrome wire
Subtopic:  Types of Processes |
 76%
From NCERT
AIPMT - 2005
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At a pressure of \(2\) atmospheres, a mass of diatomic gas \((\gamma = 1.4)\), is compressed adiabatically, causing its temperature to rise from \(27^{\circ}\mathrm{C}\) to \(927^{\circ}\mathrm{C}\). The pressure of the gas in the final state is:
1. 8 atm
2. 28 atm
3. 68.7 atm
4. 256 atm

Subtopic:  Types of Processes |
 62%
From NCERT
AIPMT - 2011
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Consider a cycle followed by an engine (figure). 

            

1 to 2 is isothermal,

2 to 3 is adiabatic,

3 to 1 is adiabatic.

Such a process does not exist, because:

(a) heat is completely converted to mechanical energy in such a process, which is not possible.
(b) In this process, mechanical energy is completely converted to heat, which is not possible.
(c) curves representing two adiabatic processes don’t intersect.
(d) curves representing an adiabatic process and an isothermal process don't intersect.



Choose the correct alternatives:
1. (a, b)
2. (a, c)
3. (b, c)
4. (c, d)

Subtopic:  First Law of Thermodynamics | Second Law of Thermodynamics |
 55%
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The figure shows the (P-V) diagram of an ideal gas undergoing a change of state from A to B. Four different paths I, II, III and IV, as shown in the figure, may lead to the same change of state.
               

(a) The change in internal energy is the same in cases IV and III but not in cases I and II.
(b) The change in internal energy is the same in all four cases.
(c) Work done is maximum in case I.
(d) Work done is minimum in case II.

 
Which of the following options contains only correct statements?

1. (b), (c), (d) 2. (a), (d)
3. (b), (c) 4. (a), (c), (d)
Subtopic:  Work Done by a Gas |
 78%
From NCERT
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The pressure and volume of a gas are changed as shown in the P-V diagram. The temperature of the gas will:

    

1.  increase as it goes from A to B.
2. increase as it goes from B to C.
3. remain constant during these changes.
4. decrease as it goes from D to A.

Subtopic:  Types of Processes |
 66%
From NCERT
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Two cylinders contain the same amount of an ideal monoatomic gas. The same amount of heat is given to two cylinders. If the temperature rise in cylinder A is T0, then the temperature rise in cylinder B will be:

1. 43T0

2. 2T0

3. T02

4. 53T0

Subtopic:  Molar Specific Heat |
 58%
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The incorrect relation is:
(where symbols have their usual meanings)

1. CP=γRγ-1

2. CP-CV=R

3. U=PfVf-PiVi1-γ

4. CV=Rγ-1

Subtopic:  Molar Specific Heat |
 81%
From NCERT
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