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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An electron collides with a hydrogen atom in its ground state and excites it to $n = 3$ . The energy given to the hydrogen atom in this inelastic collision is (neglect the recoiling of the hydrogen atom)

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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 19

Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then, the number of spectral lines in the emission spectra will be

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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 20

The radius of the orbit of an electron in a hydrogen-like atom is

4.5 a_{0}

, where

a_{0}

is Bohr radius. Its orbital angular momentum is

\frac{3 h}{2 π}

. It is given that $h$ is Planck's constant and $R$ is Rydberg constant. The possible wavelength

(s)

, when the atom de-excites, is (are)

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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 21

Find Infrared radiation will be obtained in the transition from. The transition from the state $n = 4 t o n = 3$ in a hydrogen like atom results in ultraviolet radiation.

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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 22

Hydrogen atom from the excited state comes to the ground state by emitting a photon of wavelength

λ

. If

R

is the Rydberg constant, the principal quantum number

n

of the excited state 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 23

An electron of charge

e

moves with a constant speed

v

along a circle of radius

r

, its magnetic moment will be

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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 24

The radius of hydrogen atom in its ground state is $5.3 \times 10^{11} m$ . After collision with an electron it is found to have a radius of $21.2 \times 10^{- 15} m .$ What is the principal quantum number $n$ of the final state of 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 25

According to Bohr's theory of hydrogen atom, for the electron in the $n$ -th allowed orbit the

(i)

linear momentum is proportional to

\frac{1}{n}

(ii)

radius is proportional to

n

(iii)

kinetic energy is proportional to

\frac{1}{n^{2}}

(iv)

angular moment is proportional to $n$. Choose the correct option from the codes given below.

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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 26

The shortest wavelength which can be obtained in the hydrogen spectrum is

(R = 10^{7} m^{- 1})

An electron collides with a hydrogen atom in its ground state and excites it to n=3. The energy given to the hydrogen atom in this inelastic collision is (neglect the recoiling of the hydrogen atom)

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

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An electron collides with a hydrogen atom in its ground state and excites it to $n = 3$ . The energy given to the hydrogen atom in this inelastic collision is (neglect the recoiling of the hydrogen atom)