# Thermodynamics and Statistical Physics-Black-Body Radiation and Planck's Distribution Law (GATE (Graduate Aptitude Test in Engineering) Physics): Questions 1 - 4 of 6

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## Question number: 1

» Thermodynamics and Statistical Physics » Black-Body Radiation and Planck's Distribution Law

Appeared in Year: 2016

### Write in Short

The total power emitted by a spherical black body of radius at a temperature is . Let be the total power emitted by another spherical black body of radius kept at temperature . The ratio is . (Give your answer up to two decimal places)

## Question number: 2

» Thermodynamics and Statistical Physics » Black-Body Radiation and Planck's Distribution Law

Appeared in Year: 2015

MCQ▾

### Question

For a black body radiation in a cavity, photons are created and annihilated freely as a result of emission and absorption by the walls of the cavity. This is because –

### Choices

Choice (4) Response

a.

Photons are spin – 1 particle

b.

The chemical potential of the photons is zero

c.

Photons obey Pauli exclusion principle

d.

The entropy of the photons is very large.

## Question number: 3

» Thermodynamics and Statistical Physics » Black-Body Radiation and Planck's Distribution Law

Appeared in Year: 2013

MCQ▾

### Question

Consider a gas of atoms obeying Maxwell – Boltzmann statistics. The average value of over all the momenta of each of the particles (where is a constant vector and is its magnitude, is the mass of each atom, T is temperature and is Boltzmann’s constant) is –

### Choices

Choice (4) Response

a.

Zero

b.

c.

One

d.

## Question number: 4

» Thermodynamics and Statistical Physics » Black-Body Radiation and Planck's Distribution Law

Appeared in Year: 2013

MCQ▾

### Question

A proton is confined to a cubic box, whose sides have length . What is the minimum kinetic energy of the proton? The mass of proton is and Planck’s constant is

### Choices

Choice (4) Response

a.

b.

c.

d.

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