An engine operating between the boiling and freezing points of water will have
A. efficiency more than 27%
B. efficiency less than the efficiency a Carnot engine operating between the same two temperatures.
C. efficiency equal to 27%
D. efficiency less than 27%
Solution:
The efficiency \( \eta \) of a Carnot engine is given by the formula:
\[
\eta = \left( 1 - \frac{T_2}{T_1} \right) \times 100
\]
where \( T_1 \) and \( T_2 \) are the temperatures of the hot and cold reservoirs in Kelvin.
For an engine operating between the freezing point (0°C) and the boiling point (100°C) of water:
\[
T_1 = 100 + 273 = 373 \, \text{K}, \quad T_2 = 0 + 273 = 273 \, \text{K}.
\]
Substituting these values into the formula:
\[
\eta = \left( 1 - \frac{273}{373} \right) \times 100 = 26.8\%.
\]
Thus, the efficiency of the engine is less than 27%, and the efficiency of the given engine will be less than the efficiency of a Carnot engine.
A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wien's constant, b = 2.88×106 nm-K. Then,

Match List-I with List-II.
| List-I | List-II |
| (A) Heat capacity of body | (I) \( J\,kg^{-1} \) |
| (B) Specific heat capacity of body | (II) \( J\,K^{-1} \) |
| (C) Latent heat | (III) \( J\,kg^{-1}K^{-1} \) |
| (D) Thermal conductivity | (IV) \( J\,m^{-1}K^{-1}s^{-1} \) |
Let \(\gamma_1\)be the ratio of molar specific heat at constant pressure and molar specific heat at constant volume of a monoatomic gas and \(\gamma_2\) be the similar ratio of diatomic gas. Considering the diatomic gas molecule as a rigid rotator, the ratio, \(\frac{\gamma_1}{\gamma_2}\) is :
The pressure of a gas changes linearly with volume from $A$ to $B$ as shown in figure If no heat is supplied to or extracted from the gas then change in the internal energy of the gas will be Is

What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)