ICS Part 2 Physics Chapter 20 Short Questions Preparation

12th Class Physics
Short Questions Preparation

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Online Short Questions For Chapter 9 "ICS Part 2 Physics Chapter 20 Short Questions Preparation "

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Physics - ICS Part 2 Physics Chapter 20 Short Questions Preparation

Question # 1

List of color of line spectra of an excited hydrogen atom.

Ans 1: The color of line spectrum of hydrogen atom are
- Red
- Blue
- Blue-Green
- Violet
- Ultraviolet

Question # 2

Can electron reside inside the nucleus?

Ans 1: No,electron cannot reside inside the nucleus .If electron resides inside nucleus then uncertainty in position.

Question # 3

How can spectrum of hydrogen contain so many lines,whereas hydrogen atom contain one electron?

Ans 1: The single electron in hydrogen atom occupies ground state but it can be excited to several states by absorbing energy.During de-excitation ,it can emit several lines of different wavelength.

Question # 4

What do you mean by inner shell transition?

Ans 1: A transition in which an electron from higher orbit,emits energy and accommodate a hole in the lower orbit.Such a transition is called inner shell transition.The photons emitted in such transition are called characteristic x-rays.

Question # 5

Explain why laser action could not occur without population inversion between atomic levels?

Ans 1: When a large percentage of atom or sample are in population inversion,then large number of coherent photons along same direction of motion could be obtained to form laser light,It is impossible withput population inversion.

Question # 6

What is fluorescence?

Ans 1: Fluorescence is a property of absorbing radiant energy of high frequency and re emitting energy of low frequency in the visible region of electromagnetic spectrum.

Question # 7

What do we mean when we say that the atom is excited?

Ans 1: When energy from some external source is provide to an atom in its normal state,then its electron will jump from lower energy state to higher energy state.And atom is said to be excited.

Question # 8

Bohr's theory of hydrogen atom is based upon several assumptions.Do any of these assumptions contradict classical physics?

Ans 1: Bohr's first assumptions contradicts classical physics.Bohr said that electron do not radiate energy during revolving while according to classical physics,electron radiate energy during revolving and fall into the nucleus which is impossible.

Question # 9

Briefly describe continuous x-rays.

Ans 1: Continuous X-rays is due to an effect known as Bremsstrahlung effect when fast moving electron bombarded at the target,they are suddenly slowed down on impact with the target,And due to deceleration their kinetic energy is converted into X-rays photons.

Question # 10

Write two properties of x-rays.

Ans 1:
1. They cause ionization.
2. They have very short wavelength.

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Prepare Complete Set Wise Questions For Chapter 9 "ICS Part 2 Physics Chapter 20 Short Questions Preparation "

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Set 2

10 Questions
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Set 3

10 Questions
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ICS Part 2 Physics Chapter 20 Short Questions Preparation - Set 1

Question # 1

List of color of line spectra of an excited hydrogen atom.

Ans 1: The color of line spectrum of hydrogen atom are
- Red
- Blue
- Blue-Green
- Violet
- Ultraviolet

Question # 2

Can electron reside inside the nucleus?

Ans 1: No,electron cannot reside inside the nucleus .If electron resides inside nucleus then uncertainty in position.

Question # 3

How can spectrum of hydrogen contain so many lines,whereas hydrogen atom contain one electron?

Ans 1: The single electron in hydrogen atom occupies ground state but it can be excited to several states by absorbing energy.During de-excitation ,it can emit several lines of different wavelength.

Question # 4

What do you mean by inner shell transition?

Ans 1: A transition in which an electron from higher orbit,emits energy and accommodate a hole in the lower orbit.Such a transition is called inner shell transition.The photons emitted in such transition are called characteristic x-rays.

Question # 5

Explain why laser action could not occur without population inversion between atomic levels?

Ans 1: When a large percentage of atom or sample are in population inversion,then large number of coherent photons along same direction of motion could be obtained to form laser light,It is impossible withput population inversion.

Question # 6

What is fluorescence?

Ans 1: Fluorescence is a property of absorbing radiant energy of high frequency and re emitting energy of low frequency in the visible region of electromagnetic spectrum.

Question # 7

What do we mean when we say that the atom is excited?

Ans 1: When energy from some external source is provide to an atom in its normal state,then its electron will jump from lower energy state to higher energy state.And atom is said to be excited.

Question # 8

Bohr's theory of hydrogen atom is based upon several assumptions.Do any of these assumptions contradict classical physics?

Ans 1: Bohr's first assumptions contradicts classical physics.Bohr said that electron do not radiate energy during revolving while according to classical physics,electron radiate energy during revolving and fall into the nucleus which is impossible.

Question # 9

Briefly describe continuous x-rays.

Ans 1: Continuous X-rays is due to an effect known as Bremsstrahlung effect when fast moving electron bombarded at the target,they are suddenly slowed down on impact with the target,And due to deceleration their kinetic energy is converted into X-rays photons.

Question # 10

Write two properties of x-rays.

Ans 1:
1. They cause ionization.
2. They have very short wavelength.

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ICS Part 2 Physics Chapter 20 Short Questions Preparation - Set 2

Question # 1

In which region of electromagnetic spectrum does the following series fall (a)Lyman series (b)Balmer series?

Ans 1: Balmer series falls in the visible region.
Lyman series falls in the ultraviolet region.

Question # 2

Briefly describe continuous x-rays.

Ans 1: Continuous X-rays is due to an effect known as Bremsstrahlung effect when fast moving electron bombarded at the target,they are suddenly slowed down on impact with the target,And due to deceleration their kinetic energy is converted into X-rays photons.

Question # 3

What is fluorescence?

Ans 1: Fluorescence is a property of absorbing radiant energy of high frequency and re emitting energy of low frequency in the visible region of electromagnetic spectrum.

Question # 4

Define normal population and population inversion.

Ans 1: In normal population ,the lower energy state has a greater population than the higher energy state.
Population inversion occurs when no more electron are in a higher energy state than in lower energy state.

Question # 5

Can electron reside inside the nucleus?

Ans 1: No,electron cannot reside inside the nucleus .If electron resides inside nucleus then uncertainty in position.

Question # 6

What do we mean when we say that the atom is excited?

Ans 1: When energy from some external source is provide to an atom in its normal state,then its electron will jump from lower energy state to higher energy state.And atom is said to be excited.

Question # 7

List of color of line spectra of an excited hydrogen atom.

Ans 1: The color of line spectrum of hydrogen atom are
- Red
- Blue
- Blue-Green
- Violet
- Ultraviolet

Question # 8

Write use of x-rays.

Ans 1: X-rays are used
1. To visualize the interior of the material opaque to ordinary light.
2. In computerized axial tomography.
3. In photographic films.

Question # 9

Define population inversion and metastable stable.

Ans 1: A condition of matter in which more electrons are in a high energy state than in a lower energy state is called population inversion.
A particular excited state of an atom that has longer lifetime than the ordinary excited states is called metastable state.

Question # 10

Can the electron in the ground state of hydrogen atom absorb a photon of energy 13.6 eV greater than 13.6 eV?

Ans 1: Yes an electron in the ground state of hydrogen atom can absorb a photon of energy 13.6 eV and greater than 13.6 eV.
ionization energy of hydrogen atom in ground state is 13.6 eV.So if hydrogen absorb a photon of energy greater than 13.6 eV than the surplus energy of photon appear as K.E of electron

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ICS Part 2 Physics Chapter 20 Short Questions Preparation - Set 3

Question # 1

Explain why laser action could not occur without population inversion between atomic levels?

Ans 1: When a large percentage of atom or sample are in population inversion,then large number of coherent photons along same direction of motion could be obtained to form laser light,It is impossible withput population inversion.

Question # 2

Distinguished between stimulated emission and spontaneous emission.

Ans 1: Stimulated emission: If a atom is excited for a longer lifetime of about 10^-3sec than an incident photon of energy equal to the difference of two energy levels induces the atom to decay by emitting a photon that travel in the direction of incident photon.This process is called stimulated or induced emission.
Ans 2: Spontaneous Emission: As excited is highly unstable with life time of
10^-8sec,so electron will de excite itself with emission of a photon in any arbitrarydirection is called spontaneous emission.

Question # 3

Is energy conserved when an atom emits a photon of light?

Ans 1: Yes energy is conserved when an excited atom emits a photon of light.When atom is excited ,energy is supplied .The same energy is emitted in the form of photon when it return back to its ground state.

Question # 4

Define normal population and population inversion.

Ans 1: In normal population ,the lower energy state has a greater population than the higher energy state.
Population inversion occurs when no more electron are in a higher energy state than in lower energy state.

Question # 5

What do we mean when we say that the atom is excited?

Ans 1: When energy from some external source is provide to an atom in its normal state,then its electron will jump from lower energy state to higher energy state.And atom is said to be excited.

Question # 6

Bohr's theory of hydrogen atom is based upon several assumptions.Do any of these assumptions contradict classical physics?

Ans 1: Bohr's first assumptions contradicts classical physics.Bohr said that electron do not radiate energy during revolving while according to classical physics,electron radiate energy during revolving and fall into the nucleus which is impossible.

Question # 7

Write two postulate of Bohr's model of H-atom.

Ans 1:
- An electron ,bound to the nucleus in an atom,can moved around the nucleus in certain circular orbits without radiating,These orbits are called the discrete stationary orbits.
- Only those stationary orbits are allowed for which orbital angular momentum is equal to an integral multiple mvr=nh/2π.

Question # 8

Define continuous spectrum.

Ans 1: The radiation emitted by continuous media such as ''Black Body" forms a continuous spectrum,In continuousspectrum wavelengths of radiations can not be observed in discrete lines.

Question # 9

List of color of line spectra of an excited hydrogen atom.

Ans 1: The color of line spectrum of hydrogen atom are
- Red
- Blue
- Blue-Green
- Violet
- Ultraviolet

Question # 10

Write use of x-rays.

Ans 1: X-rays are used
1. To visualize the interior of the material opaque to ordinary light.
2. In computerized axial tomography.
3. In photographic films.

Submit

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ICS Part 2 Physics Chapter 20 Short Questions Preparation

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ICS Part 2 Physics Chapter 20 Short Questions Preparation

12th Class PhysicsShort Questions Preparation

12th Class Physics Chapter Wise Preparation

Online Short Questions For Chapter 9 "ICS Part 2 Physics Chapter 20 Short Questions Preparation "

Physics - ICS Part 2 Physics Chapter 20 Short Questions Preparation

List of color of line spectra of an excited hydrogen atom.

Can electron reside inside the nucleus?

How can spectrum of hydrogen contain so many lines,whereas hydrogen atom contain one electron?

What do you mean by inner shell transition?

Explain why laser action could not occur without population inversion between atomic levels?

What is fluorescence?

What do we mean when we say that the atom is excited?

Bohr's theory of hydrogen atom is based upon several assumptions.Do any of these assumptions contradict classical physics?

Briefly describe continuous x-rays.

Write two properties of x-rays.

Prepare Complete Set Wise Questions For Chapter 9 "ICS Part 2 Physics Chapter 20 Short Questions Preparation "

Set 1

Set 2

Set 3

ICS Part 2 Physics Chapter 20 Short Questions Preparation - Set 1

List of color of line spectra of an excited hydrogen atom.

Can electron reside inside the nucleus?

How can spectrum of hydrogen contain so many lines,whereas hydrogen atom contain one electron?

What do you mean by inner shell transition?

Explain why laser action could not occur without population inversion between atomic levels?

What is fluorescence?

What do we mean when we say that the atom is excited?

Bohr's theory of hydrogen atom is based upon several assumptions.Do any of these assumptions contradict classical physics?

Briefly describe continuous x-rays.

Write two properties of x-rays.

ICS Part 2 Physics Chapter 20 Short Questions Preparation - Set 2

In which region of electromagnetic spectrum does the following series fall (a)Lyman series (b)Balmer series?

Briefly describe continuous x-rays.

What is fluorescence?

Define normal population and population inversion.

Can electron reside inside the nucleus?

What do we mean when we say that the atom is excited?

List of color of line spectra of an excited hydrogen atom.

Write use of x-rays.

Define population inversion and metastable stable.

Can the electron in the ground state of hydrogen atom absorb a photon of energy 13.6 eV greater than 13.6 eV?

ICS Part 2 Physics Chapter 20 Short Questions Preparation - Set 3

Explain why laser action could not occur without population inversion between atomic levels?

Distinguished between stimulated emission and spontaneous emission.

Is energy conserved when an atom emits a photon of light?

Define normal population and population inversion.

What do we mean when we say that the atom is excited?

Bohr's theory of hydrogen atom is based upon several assumptions.Do any of these assumptions contradict classical physics?

Write two postulate of Bohr's model of H-atom.

Define continuous spectrum.

List of color of line spectra of an excited hydrogen atom.

Write use of x-rays.

ICS Part 2 Physics Chapter 20 Short Questions Preparation

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