List of top Geophysics Questions on Thermodynamics

Which of the following is incorrect thermodynamical relation of Maxwell?

An iron furnace radiates \(42.5\) calories per second through an opening of cross-section \(1\ \text{cm}^2\). If the relative emittance of the furnace is \(0.80\), the temperature of furnace is given Stefan's constant \(\sigma=1.36\times10^{-8}\ \text{cal/m}^2\text{s K}^4\):

Calculate the entropy change in the following. Given latent heat of steam is \(540\ \text{cal/g}\), latent heat of ice is \(80\ \text{cal/g}\).
A. \(10g\) of water at \(100^\circ C\) converted to steam at same temperature,
B. \(20g\) of water at \(100^\circ C\) converted to steam at same temperature,
C. \(1g\) of ice at \(0^\circ C\) converted into water at \(0^\circ C\),
D. \(10g\) of ice at \(0^\circ C\) converted into water at \(0^\circ C\).

Which of the following is/are correct \(Tds\) equation?

Which of the following is reversible process?

One mole of an ideal gas expands isothermally to ten times its initial volume. The change in entropy in terms of \(R\) is:

Work done in compressing adiabatically 1g of air, initially at NTP to one fourth of its original volume is: (take density of air = 0.0001465 g/cm³ and \(\gamma\) = 1.5)

Change of entropy of a perfect gas for isochoric process is

The ratio of adiabatic to the isobaric coefficient of expansion is

Which of following is correct form of first TdS equation ?

Match List-I with List-II

\[ \begin{array}{|l|l|} \hline \textbf{List-I} & \textbf{List-II} \\ \hline (A) \; \text{Classius Clapeyron equation} & (I) \; PV^\gamma = \text{constant} \\ (B) \; \text{Gibbs Function} & (II) \; U + PV \\ (C) \; \text{Enthalpy} & (III) \; U - TS + PV \\ (D) \; \text{Adiabatic change in Perfect Gas} & (IV) \; \dfrac{dP}{dT} = \dfrac{L}{T (V_2 - V_1)} \\ \hline \end{array} \]
Choose the correct answer from the options given below:

The energy radiated per minute from the filament of an incandescent lamp at 2000 K, surface area \( 4 \times 10^{-5} \) m² and relative emittance is 0.85, will be (Given Stefan's constant \( \sigma = 5.7 \times 10^{-8} \) Jm⁻²s⁻¹K⁻⁴)