Thermodynamics

The temperature inside a refrigerator is $t_2\,^\circ$C and the room temperature is $t_1\,^\circ$C. The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be

A refrigerator works between $4\,^\circ$C and $30\,^\circ$C. It is required to remove 600 calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required is: (Take $1$ cal $=4.2$ J)

A gas is compressed isothermally to half its initial volume. The same gas is compressed separately through an adiabatic process until its volume is again reduced to half. Then:

The figure shows a $P$-$V$ diagram with three isotherms at $700$ K, $500$ K and $300$ K. Four processes I, II, III and IV start from a common initial state. Match each process with its type:\\ List-I (Process): I, II, III, IV\\ List-II (Type): (a) Adiabatic, (b) Isobaric, (c) Isochoric, (d) Isothermal.\\ Which of the following is the correct matching?

A Carnot engine having an efficiency of $\dfrac{1}{10}$ as a heat engine is used as a refrigerator. If the work done on the system is $10$ J, the amount of energy absorbed from the reservoir at lower temperature is

The volume ($V$) of a monatomic gas varies with its temperature ($T$), as shown in the graph (a straight line through the origin, from A to B, i.e. an isobaric process). The ratio of the work done by the gas to the heat absorbed by it, when it goes from A to B, is

The efficiency of an ideal heat engine working between the freezing point and boiling point of water is

$0.1$ g of water at $100\,^\circ$C and normal pressure ($1.013\times 10^{5}$ N/m$^2$) requires $54$ cal to convert into steam at $100\,^\circ$C. If the volume of the steam produced is $167.1$ cc, the change in internal energy is

In which of the following processes, heat is neither absorbed nor released by a system?

An ideal gas expands isothermally from $10^{-3}$ m$^3$ to $10^{-2}$ m$^3$ at $300$ K against a constant external pressure of $10^{5}$ N/m$^2$. The work done ON the gas is

An ideal gas undergoes four different processes from the same initial state (see figure). The processes are adiabatic, isothermal, isobaric and isochoric. The curve which represents the adiabatic process among $1, 2, 3, 4$ is

A Carnot engine has an efficiency of $50\%$ when its source is at $327\,^\circ$C. The temperature of the sink is

For the given cycle, the work done during the isobaric process is

Reversible expansion of an ideal gas under isothermal and adiabatic conditions is shown in the figure, where $AB$ is the isothermal expansion and $AC$ is the adiabatic expansion, both starting from the common state $A$. Which of the following options is NOT correct?

A thermodynamic system is taken through the cycle $abcda$. The work done by the gas along the path $bc$ is

Two gases A and B are filled at the same pressure in separate cylinders with movable pistons of radius $r_A$ and $r_B$, respectively. On supplying an equal amount of heat to both gases reversibly at constant pressure, the pistons of A and B are displaced by $16$ cm and $9$ cm, respectively. If the change in their internal energy is the same, then the ratio $\dfrac{r_A}{r_B}$ is

One mole of an ideal monatomic gas undergoes a cyclic process shown in the figure (rectangle $a\to b\to c\to d$ in the $P$–$V$ plane, with $P$ in N m$^{-2}$ between $100$ and $300$, and $V$ in m$^3$ between $2$ and $5$). The total heat supplied to the gas is:

An electric heater supplies heat to a system at a rate of $100$ W. If the system performs work at a rate of $75$ J/s, the rate at which internal energy increases is

At a certain temperature, during a process, $500$ J is absorbed by the system and $200$ J of work is done by the system. The change in internal energy of the system is

In an adiabatic expansion, the temperature of one mole of an ideal monatomic gas ($\gamma=5/3$) decreases from $60\,$K to $50\,$K. The work done by the gas in the process is: [Take $R=8.3\,\text{J mol}^{-1}\text{K}^{-1}$]