Carnot Engine

A Carnot engine, whose efficiency is$40\%$, takes in heat from a source maintained at a temperature of $500 \mathrm{K}$. It is desired to have an engine of efficiency $60\%$. Then, the intake temperature for the same exhaust (sink) temperature must be
 

A carnot engine, whose efficiency is $40\%$, takes in heat from a source maintained at a temperature of $500 \mathrm{K}$. It is desired to have an engine of efficiency $60\%$. Then, the intake temperature for the same exhaust (sink) temperature must be

Helium gas goes through a cycle $ABCDA$ (consisting of two isochoric and two isobaric lines) as shown in Fig. $20.62$. Efficiency of the cycle is nearly. (Assume the gas to be close to ideal gas)

A carnot engine takes $3\times {10}^6 \mathrm{cal}$ of heat from a reservoir of $627°\mathrm{C}$ and given it to a sink at $27°\mathrm{C}$. The Work done by the engine is

A carnot engine absorbs an amount $Q$ of heat from $a$ reservoir at an absolute temperature $T$ and rejectes heat to a sink at a temperature of $\frac{T}{3}$. The amount of heat rejected is

A Carnot engine whose low temperature reservoir is at $7°\mathrm{C}$ has an efficiency of $50\%$. It is desired to increase the efficiency to $70\%$. By how many degree should the temperature of high temperature reservoir be increased ?

A Carnot reversible engine converts $\frac{1}{6}$ of heat input into work. When the temperature of the sink is reduced by $62 \mathrm{K}$, the efficiency of carnot cycle becomes $\frac{1}{3}$. The temperature of the source and sink will be 

Three designs are proposed for an engine operating between $500 \mathrm{K}$ and $300 \mathrm{K}$. For $1 \mathrm{kcal}$ of heat input, design A claims to produce $3000\mathrm{J}$ of work, design $B$ claims to produce $2000\mathrm{J}$ of work and design $C$ claims to produce $1680\mathrm{J}$ of work. The design which is possible.

The efficiency of a Carnot's heat engine is $0.5$, when the temperature of the source is $T_1$ and that of sink is $T_2$. The efficiency of another carnot engine is also $0.5$ The temperatures of source and sink of the second engine are respectively

A carnot engine operating between temperatures $T_1$ and $T_2$ has efficiency $\frac{1}{6}$. When $T_2$ is lowered by $62 \mathrm{K}$, its efficiency increases to $\frac{1}{3}$. Then $T_1$ and $T_2$ are, respectively

An ideal refrigerator has a freezer at a temperature of $-{13}^{\circ }C$. The coefficient of performance of the engine is $5$. The temperature of the air (to which heat is rejected) is :

An ideal carnot engine takes heat from a source at $317°\mathrm{C}$ does some work and delivers the remaining energy to a heat sink at $117°\mathrm{C}$. If $500 \mathrm{k} \mathrm{cal}$  of heat is taken from the source, how much work is done ? How much heat is delivered to the sink ?

Compare the actual efficiency with the theoretical maximum efficiency. A carnot-type engine is designed to operate between $480$ and $300 \mathrm{K}$. Assuming that the engine actually produces $1.2 \mathrm{kJ}$ of mechanical energy per kilocalorie of heat absorbed.

A carnot engine operates between $317°\mathrm{C}$ and $67°\mathrm{C}$. What is its efficiency ?

What is a carnot refrigerator ? Find the relation between the coefficient of performance$\left(\eta \text{'}\right)$ of a carnot refrigerator and the efficiency of a carnot heat engine$\left(\eta \right)$.

What is second law of thermodynamics, does it provide which first law cannot?

What is carnot theorem ?

Draw the $p-V$ diagram and $T-S$ diagram of a carnot cycle and explain these. What is the efficiency of a carnot engine.

Oceans contain enormous thermal energies. Can this energy be utilised to run a heat engine ?

What is the usefulness of a Carnot engine if it cannot be realised in practice?