GATE PH topic:thermodynamics-statistical-physics PYQs & Answers

Questions 1–10 of 60. Imported answers require independent review unless marked reviewed.

Consider the Otto cycle for an ideal gas engine consisting of two quasistatic adiabatic and two quasistatic isochoric processes. The correct temperature-entropy (T-S) phase diagram for the cycle is

Your answerChoose one option.

Diagram for Physics question 17 (figure 2)

Diagram for Physics question 17 (figure 3)

Diagram for Physics question 17 (figure 4)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The formula for energy

of a photon gas at temperature

in a two-dimensional box at equilibrium with

denoting the density of states of photons is given below where symbols

and

have their standard meaning. The specific heat (

) of this photon gas obeys

Your answerChoose one option.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A gas of non-interacting

atoms (of mass

) is in a three-dimensional trap whose energy levels can be approximated by those of a harmonic oscillator potential

. The chemical potential of the gas at

K is

Your answerChoose one option.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Schematic variation of the specific heat

of an ideal gas of diatomic molecules with temperature

is shown in the figure below. For rotational energy

and vibrational energy

of the molecule, which of the following options is/are correct? Here

is the Boltzmann constant.

Your answerSelect all correct options. You can choose more than one.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The specific heat

of one mole of a material as a function of temperature

is given as

, where

and

. When

is changed from 1 K to 10 K at constant pressure, then the change in entropy

(rounded off to one decimal place) is ____

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Two identical particles with a fixed total energy

are in thermal equilibrium in a one-dimensional harmonic oscillator potential

. Let the entropy of the particles be denoted by

if they are fermions with spin

and

if they are bosons with spin 0. Then, which of the following options is correct? (

is the Boltzmann constant)

Your answerChoose one option.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A gas of

classical particles that can occupy energy levels

and

is in equilibrium with a reservoir at temperature

. From the schematics shown below, choose the correct dependence of the internal energy

Your answerChoose one option.

Diagram for Physics question 45 (figure 2)

Diagram for Physics question 45 (figure 3)

Diagram for Physics question 45 (figure 4)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Consider the distribution of outcomes generated by

(

) independent throws of (i) a coin or (ii) a six-sided dice. A coin (dice) is unbiased if (all) its sides have equal probability to show up in a throw; it is biased otherwise. For the cases (i) and (ii) above, which of the following statements is/are true?

Your answerSelect all correct options. You can choose more than one.

The entropy of an unbiased coin is smaller than that of an unbiased dice.

The entropy of an unbiased coin is greater than that of an unbiased dice.

The entropy of a biased dice is smaller than that of an unbiased dice.

The entropy of a biased coin is greater than that of an unbiased coin.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The Joule-Thomson expansion of a gas is

Your answerChoose one option.

Isentropic

Isenthalpic

Isobaric

Isochoric

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A schematic Pressure-Temperature diagram of water is shown in the figure. Which of the following option(s) is/are correct?

Your answerSelect all correct options. You can choose more than one.

Clausius-Clapeyron equation is valid across the melting curve and the vaporization curve

Melting curve has the highest slope

The critical point exists only for the vaporization curve

Clausius-Clapeyron equation is not valid across the melting curve and the vaporization curve

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE PH topic:thermodynamics-statistical-physics PYQs

How to practice topic:thermodynamics-statistical-physics

Question 17

Question 18

Question 20

Question 25

Question 33

Question 42

Question 45

Question 53

Question 15

Question 26