An ideal gas is made to undergo a cycle depicted by the \((P-V)\) diagram alongside. If the curved line from \(A\) to \(B\) is adiabatic, then:
1. | the efficiency of this cycle is given by unity as no heat is released during the cycle. |
2. | heat is absorbed in the upper part of the straight-line path and released in the lower. |
3. | if \(T_1\) and \(T_2\) are the maximum and minimum temperatures reached during the cycle, then the efficiency is given by, \(1-\frac{T_2}{T_1}.\) |
4. | the cycle can only be carried out in the reverse direction as shown in the figure. |
In this \((P-V)\) diagram below the dashed curved line is adiabatic.
For a process, that is described by a straight line joining two points \(X\) and \(Y\) on the adiabat (solid line In the diagram) heat is:
(Consider the variations in temperature from \(X\) to \(Y\) along the straight line.)
1. | \(X\) to \(Y.\) | absorbed throughout from
2. | \(X\) to \(Y.\) | released throughout from
3. | \(X\) up to an intermediate point \(Z\) (not shown In the figure) and then released from \(Z\) to \(Y.\) | absorbed from
4. | \(X\) up to an Intermediate point \(Z\) (not shown in the figure) and then absorbed from \(Z\) to \(Y.\) | released from
An ideal gas is taken reversibly around the cycle \(a\text-b\text-c\text-d\text-a\) as shown on the temperature \((T)\) - entropy \((S)\) diagram.
The most appropriate representation of the above cycle on an internal energy \((U)\) - volume \((V)\) diagram is:
1. | 2. | ||
3. | 4. |
1. | \(W_1<W_2<W_3\) | 2. | \(W_2<W_1=W_3\) |
3. | \(W_2<W_1<W_3\) | 4. | \(W_1>W_2>W_3\) |
Thermodynamic processes are indicated in the following diagram:
Match the following:
Column-I | Column-II | ||
P. | Process I | a. | Adiabatic |
Q. | Process II | b. | Isobaric |
R. | Process III | c. | Isochoric |
S. | Process IV | d. | Isothermal |
P | Q | R | S | |
1. | c | a | d | b |
2. | c | d | b | a |
3. | d | b | a | c |
4. | a | c | d | b |
The Carnot cycle (reversible) of gas is represented by a pressure-volume curve as shown. Consider the following statements:
I. | Area \(ABCD\) = Work done on the gas |
II. | Area \(ABCD\) = Net heat absorbed |
III. | Change in the internal energy in cycle = \(0\) |
Which of the statement(s) given above is/are correct?
1. | I only | 2. | II only |
3. | II and III | 4. | I, II, and III |
The figure shows the \((P\text-V)\) diagram of an ideal gas undergoing a change of state from \(A\) to \(B\). Four different paths \(\mathrm{I, II, III}\) and \(\mathrm{IV}\), as shown in the figure, may lead to the same change of state.
(a) | The change in internal energy is the same in cases \(\mathrm{IV}\) and \(\mathrm{III}\) but not in cases \(\mathrm{I}\) and \(\mathrm{II}\). |
(b) | The change in internal energy is the same in all four cases. |
(c) | Work done is maximum in case \(\mathrm{I}\). |
(d) | Work done is minimum in case \(\mathrm{II}\). |
Which of the following options contains only correct statements?
1. (b), (c), (d)
2. (a), (d)
3. (b), (c)
4. (a), (c), (d)
Match the thermodynamic processes taking place in a system with the correct conditions. In the table, \(\Delta Q\) is the heat supplied, \(\Delta W\) is the work done and \(\Delta U\) is the change in internal energy of the system.
Process | Condition | ||
(I) | Adiabatic | (A) | \(\Delta W=0\) |
(II) | Isothermal | (B) | \(\Delta Q=0\) |
(III) | Isochoric | (C) | \(\Delta U\neq0, \Delta W\neq0,\Delta Q\neq0\) |
(IV) | Isobaric | (D) | \(\Delta U=0\) |
1. | (I) – (B), (II) – (A), (III) – (D), (IV) – (C) |
2. | (I) – (A), (II) – (A), (III) – (B), (IV) – (C) |
3. | (I) – (A), (II) – (B), (III) – (D), (IV) – (D) |
4. | (I) – (B), (II) – (D), (III) – (A), (IV) – (C) |
Consider the following two statements.
(A): | If heat is added to a system, its temperature must increase. |
(B): | If positive work is done by a system in a thermodynamic process, its volume must increase. |
1. | Both A and B are correct. |
2. | A is correct but B is wrong. |
3. | B is correct but A is wrong. |
4. | Both A and B are wrong. |
Figure shows P-T diagram for given mass of an ideal gas for the process A→B. During this process, density of the gas is
1. Decreasing
2. Increasing
3. Constant
4. First decreasing then increasing