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

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 # 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

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 # 4

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 # 5

How does a K_ax-rays differ K_bX-rays?

Ans 1: When an electron from L -shell jumps to occupy the hole in K- shell K_ax-rays is emitted .
And
When an electron from M -shells jumps to occupy the hole in K-Shell K_bX-rays is emited.

Question # 6

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 # 7

What are the advantages of laser over ordinary light?

Ans 1: Laser light has many advantages over ordinary light such as laser light is
1. Coherent
2. Intense
3. Monochromatic
4. Unidirectional

Question # 8

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 # 9

Can x-rays be reflected,diffracted polarized just like any other eaves?Explain

Ans 1: Yes x rays can be reflected,refracted diffracted by crystal only and polarized just like any other waves.

Question # 10

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.

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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

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

Question # 1

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 # 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

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 # 4

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 # 5

How does a K_ax-rays differ K_bX-rays?

Ans 1: When an electron from L -shell jumps to occupy the hole in K- shell K_ax-rays is emitted .
And
When an electron from M -shells jumps to occupy the hole in K-Shell K_bX-rays is emited.

Question # 6

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 # 7

What are the advantages of laser over ordinary light?

Ans 1: Laser light has many advantages over ordinary light such as laser light is
1. Coherent
2. Intense
3. Monochromatic
4. Unidirectional

Question # 8

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 # 9

Can x-rays be reflected,diffracted polarized just like any other eaves?Explain

Ans 1: Yes x rays can be reflected,refracted diffracted by crystal only and polarized just like any other waves.

Question # 10

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.

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

Question # 1

Differentiate between Line and Band spectrum.

Ans 1: Line spectrum: When electron jumps from higher orbit to lower orbit ,it emits energy,This emission of energy constitutes spectral line,This is called the line spectrum.
Ans 2: Band spectrum:is produced by molecules,They are the groups of lines which are closely spaced to another.

Question # 2

Give two uses of laser in medicine and industry.

Ans 1: Laser is used
1. For welding detached retinas
2. To destroy cancerous and precancerous cells.

Question # 3

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 # 4

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 # 5

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

Question # 6

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 # 7

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 # 8

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 # 9

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 # 10

Define characteristics of X-rays and continuous x-rays.

Ans 1: Chararcterstics X-rays: The x-rays emitted from inner shell transitions are called characteristics x-rays and their energy depends on the type of target material.
Continuous X-rays:The x-rays emitted having continuous range of frequencies due to bremsstrahlung effect are called continuous x rays.

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

Question # 1

Write two properties of x-rays.

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

Question # 2

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 # 3

What are the difference between laser light and ordinary light?

Ans 1: The laser light is intense ,unidirectional and phase coherent ,so it does bit spread as compared to ordinary light.
The energy of laser can be focused at a point to get enough heat for welding which is not possible with ordinary light.
A laser beam is used as a surgical tool for welding detached retina which ordinary light can not do.

Question # 4

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 # 5

what is Spectroscopy?

Ans 1: It is that branch of physics which deals with the production,measurement and interaction of electromagnetic radiation emitted or absorbed by atom is called Spectroscopy.

Question # 6

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 # 7

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 # 8

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 # 9

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 # 10

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.

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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

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

Briefly describe continuous x-rays.

Define continuous spectrum.

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

How does a Kax-rays differ KbX-rays?

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

What are the advantages of laser over ordinary light?

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

Can x-rays be reflected,diffracted polarized just like any other eaves?Explain

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

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

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

Briefly describe continuous x-rays.

Define continuous spectrum.

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

How does a Kax-rays differ KbX-rays?

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

What are the advantages of laser over ordinary light?

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

Can x-rays be reflected,diffracted polarized just like any other eaves?Explain

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

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

Differentiate between Line and Band spectrum.

Give two uses of laser in medicine and industry.

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

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

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

Define population inversion and metastable stable.

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

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

Distinguished between stimulated emission and spontaneous emission.

Define characteristics of X-rays and continuous x-rays.

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

Write two properties of x-rays.

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

What are the difference between laser light and ordinary light?

Define population inversion and metastable stable.

what is Spectroscopy?

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

Define normal population and population inversion.

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

Distinguished between stimulated emission and spontaneous emission.

What do you mean by inner shell transition?

ICS Part 2 Physics Chapter 20 Short Questions Preparation

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12th Class Physics
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How does a K_ax-rays differ K_bX-rays?

How does a K_ax-rays differ K_bX-rays?