Two Carnot engines x and y are working between the same source temperature \(T_1\) and the same sink temperature \(T_2\). If the temperature of the source in Carnot engine x is increased by \(\Delta T\), and in the Carnot engine y, the temperature of the sink is increased by\(\Delta T\), then the efficiency of x and y becomes \(\eta_\mathrm x\) and\(\eta_\mathrm y\). Then:

1. \(\eta_{\mathrm{x}}=\eta_{\mathrm{y}}\)
2. \(\eta_{\mathrm{x}}<\eta_{\mathrm{y}}\)
3. \(\eta_{\mathrm{x}}>\eta_{\mathrm{y}}\)
4.  The relation between \(\eta_{\mathrm{x}}\) and \(\eta_{\mathrm{y}}\) depends on the nature of the working substance

Subtopic:  Carnot Engine |
 59%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


In the P-V graph shown for an ideal diatomic gas, the change in the internal energy is:
                               
 

1. \(\frac{3}{2}P(V_2-V_1)\) 2. \(\frac{5}{2}P(V_2-V_1)\)
3. \(\frac{3}{2}P(V_1-V_2)\) 4. \(\frac{7}{2}P(V_1-V_2)\)
Subtopic:  Molar Specific Heat |
 80%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


The first law of thermodynamics is based on:

1. the concept of temperature.
2. the concept of conservation of energy.
3. the concept of working of heat engine.
4. the concept of entropy.

Subtopic:  First Law of Thermodynamics |
 92%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


advertisementadvertisement

The efficiency of an ideal heat engine is less than 100% because of:

1.  the presence of friction.
2.  the leakage of heat energy.
3.  unavailability of the sink at zero kelvin.
4.  All of these

Subtopic:  Carnot Engine |
 83%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


A heat engine operates between the temperatures of 300 K and 500 K. If it extracts 1200 J of heat energy from the source, then the maximum amount of work that can be done by the engine is:

1. 720 J

2. 520 J

3. 480 J

4. 200 J

Subtopic:  Carnot Engine |
 82%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


If 3 moles of a monoatomic gas do 150 J of work when it expands isobarically, then a change in its internal energy will be:

1. 100 J 2. 225 J
3. 400 J 4. 450 J
Subtopic:  Molar Specific Heat |
 77%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


advertisementadvertisement

In the case of free expansion, when a sample of gas expands suddenly, the change in internal energy of the gas will be:

1. Positive

2. Negative

3. Zero

4. May be positive or negative

Subtopic:  First Law of Thermodynamics |
 61%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


The work done for the given process AB is:

   

1. 6P0V0

2. 5P0V0

3. 3P0V0

4. 2P0V0

Subtopic:  Work Done by a Gas |
 52%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


The efficiency of a Carnot heat engine working between the temperatures \(27^{\circ}\mathrm{C}\) and \(227^{\circ}\mathrm{C}\) is:
1. 0.1
2. 0.6
3. 0.2
4. 0.4

Subtopic:  Carnot Engine |
 81%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


advertisementadvertisement

Work done during the given cycle is:
                               
1. 4P0V0

2. 2P0V0

3. 12P0V0

4. P0V0

Subtopic:  Work Done by a Gas |
 78%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.