In practice, all heat engines have efficiency less than that of a Carnot engine because
A
Carnot engine is irreversible
B
A reversible process can never be attained in a real world
C
Irreversible engine has higher efficiency than reversible engine
D
Efficiency of Camot engine is always one
Medium
Download our app for free and get started
B
A reversible process can never be attained in a real world
b (b)
Theoreticel engine tht operates on the revasibh Cannot Cyele.
$A B$ (Infinite steps)
$\eta=1-\frac{T_l}{T_s}$
$T=0\,K$
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Two carnot engines $A$ and $B$ operate in series such that engine $A$ absorbs heat at $T_{1}$ and rejects heat to a sink at temperature $T$. Engine $B$ absorbs half of the heat rejected by engine $A$ and rejects heat to the sink at ${T}_{3}$. When workdone in both the cases is equal, the value of ${T}$ is
A thermodynamic system is taken form an initial state $i$ with internal energy $U_1=100 \ J$ to the final state along two different paths iaf and ibf, as schematically shown in the fire. The work done by the system along the paths $af$, ib and bf are $W _{ af }=200 \ J , W _{ ID }=50 \ J$ and $W _{ br }=100 \ J$ respectively. The heat supplied to the system along the path iaf, ib and bf are $Q_{\mid a t l} Q_{b r}$ and $Q_{10}$ respectively. If the internal energy of the sytem in the state $b$ is $U_b=$ $200 \ J$ and $Q_{l a t}=500 \ J$, the ratio $Q_{b J} / Q_{10}$ is:
In a mechanical refrigerator, the low temperature coils are at a temperature of $-23°C$ and the compressed gas in the condenser has a temperature of $27°C.$ The theoretical coefficient of performance is
The adjoining figure shows the $P-V$ diagram for a fixed mass of an ideal gas undergoing cyclic process. $AB$ represents isothermal process and $CA$ represents isochoric process.Which of the graph shown in the following figures represents the $P-T$ diagram of the cyclic process ?
Let $\eta_{1}$ is the efficiency of an engine at $T _{1}=447^{\circ}\,C$ and $T _{2}=147^{\circ}\,C$ while $\eta_{2}$ is the efficiency at $T _{1}=947^{\circ}\,C$ and $T _{2}=47^{\circ}\,C$. The ratio $\frac{\eta_{1}}{\eta_{2}}$ will be.
A thermally isolated cylindrical closed vessel of height $8 m$ is kept vertically. It is divided into two equal parts by a diathermic $($perfect thermal conductor$)$ frictionless partition of mass $8.3 kg$. Thus the partition is held initially at a distance of $4 m$ from the top, as shown in the schematic figure below. Each of the two parts of the vessel contains $0.1$ mole of an ideal gas at temperature $300 K$. The partition is now released and moves without any gas leaking from one part of the vessel to the other. When equilibrium is reached, the distance of the partition from the top $($in $m )$ will be $. . . . . ($take the acceleration due to gravity $=10 ms ^{-2}$ and the universal gas constant $=8.3 J mol ^{-1} K ^{-1} ).$
The above $P-V$ diagram represents the thermodynamic cycle of an engine, operating with an ideal monatomic gas. The amount of heat, extracted from the source in a single cycle is