What is rest mass of photon?

By nature, photons are just energy packets which are travelling continuously. Therefore photons have zero rest mass as they are never stationary. Note-According to Einstein's quantum theory light propagates in the form of packets i.e. quanta of energy, which is called photon. The rest mass of photons is being zero. It can be shown, according to the relativity theory of light. According to the relativistic theory equation, the mass of the photon is computed as: m = m 0 1 − ( c 2 / v 2 ) m 0 = m 1 − ( c 2 / v 2 ) when v = 0 ; So m 0 = 0 Where m 0 is the rest mass of the Photon .

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Let the potential energy of hydrogen atom in the ground state be regarded as zero. Then the potential energy in the first excited state will be

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Important Questions on Bohr Model, X-Ray Spectra, Wave-Particle Duality

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 20 - Bohr Model, X-Ray Spectra, Wave-Particle Duality>EXERCISE 20>Q 48

As per Bohr model, the minimum energy (in $e V$ ) required to remove an electron from the ground state of doubly ionised $L i$ atom $(Z = 3)$ is

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 20 - Bohr Model, X-Ray Spectra, Wave-Particle Duality>EXERCISE 20>Q 49

The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true?

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 20 - Bohr Model, X-Ray Spectra, Wave-Particle Duality>EXERCISE 20>Q 50

A hydrogen atom and a

{Li}^{2 +}

ion are both in their second excited state. If

E_{H} a n d E_{L i}

their respective energies and

l_{H}

and

l_{Li}

are their respective electronic angular momentum, then

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 20 - Bohr Model, X-Ray Spectra, Wave-Particle Duality>EXERCISE 20>Q 51

The electric potential between a proton and an electron is given by

V = V \ln \frac{r}{r_{0}}

, where

r_{0}

is a constant. Assuming Bohr's model to be applicable, write variation of

r_{n}

with

n

where

n

is the principal quantum number

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 20 - Bohr Model, X-Ray Spectra, Wave-Particle Duality>EXERCISE 20>Q 52

A photon collides with a stationary hydrogen atom in ground state inelastically. Energy of the colliding photon is

10.2 eV .

After a time interval of order of microsecond another photon collides with the same hydrogen atom inelastically with an energy of

15 eV

. What will be absorbed by the detector?

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 20 - Bohr Model, X-Ray Spectra, Wave-Particle Duality>EXERCISE 20>Q 53

In the Bohr model of the hydrogen atom

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 20 - Bohr Model, X-Ray Spectra, Wave-Particle Duality>EXERCISE 20>Q 54

The ratio of their de-Broglie wavelength

\frac{λ_{e}}{λ p}

is when an electron of mass

m_{e}

and a proton of mass

m_{p}

are moving with the same speed.

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 20 - Bohr Model, X-Ray Spectra, Wave-Particle Duality>EXERCISE 20>Q 55

The ratio of the de-Broglie wavelength associated with these particles, when an electron and a proton are moving in the same direction with same kinetic energy.

Let the potential energy of hydrogen atom in the ground state be regarded as zero. Then the potential energy in the first excited state will be

Important Questions on Bohr Model, X-Ray Spectra, Wave-Particle Duality

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