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

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 # 2

What is meant by line spectrum? How line spectrum can be used for the identification of elements?

Ans 1: When an electron jumps from higher energy state to lower energy state than emits energy and make a spectral line.
E₂- E₁_=hf
_{This is called line spectrum.And different elements emit line spectrum of different wavelengths,So they can be identifiedeasily.}

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

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

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 # 6

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 # 7

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 # 8

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 # 9

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 # 10

Write two properties of x-rays.

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

Submit

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

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 # 2

What is meant by line spectrum? How line spectrum can be used for the identification of elements?

Ans 1: When an electron jumps from higher energy state to lower energy state than emits energy and make a spectral line.
E₂- E₁_=hf
_{This is called line spectrum.And different elements emit line spectrum of different wavelengths,So they can be identifiedeasily.}

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

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

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 # 6

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 # 7

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 # 8

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 # 9

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 # 10

Write two properties of x-rays.

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

Submit

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

Question # 1

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 # 2

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 # 3

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 # 4

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 # 5

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 # 6

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 # 7

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 # 8

Write two properties of x-rays.

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

Question # 9

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.

Question # 10

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.

Submit

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

Question # 1

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 # 2

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 # 3

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 # 4

What is meant by lasing action?

Ans 1: When a large percentage of atom or sample is in population inversion then large number of coherent photons along same direction of motion could be obtained to form laster light,The combination of spontaneous emission of first and then stimulated emission cause the laser to generate coherent beam of light at a single frequency which is called lasing action.

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

What is meant by line spectrum? How line spectrum can be used for the identification of elements?

Ans 1: When an electron jumps from higher energy state to lower energy state than emits energy and make a spectral line.
E₂- E₁_=hf
_{This is called line spectrum.And different elements emit line spectrum of different wavelengths,So they can be identifiedeasily.}

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

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 # 10

Write down use of laser in industry.

Ans 1: It can be used for telecommunication in fibre optics.
It is used to read bar codes,
It is used to generate 3D image of objects by holography.

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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

Define continuous spectrum.

What is meant by line spectrum? How line spectrum can be used for the identification of elements?

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

Define population inversion and metastable stable.

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.

Give two uses of laser in medicine and industry.

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

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

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

Define continuous spectrum.

What is meant by line spectrum? How line spectrum can be used for the identification of elements?

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

Define population inversion and metastable stable.

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.

Give two uses of laser in medicine and industry.

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

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

Write two properties of x-rays.

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

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

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

what is Spectroscopy?

Briefly describe continuous x-rays.

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

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

How does a Kax-rays differ KbX-rays?

Write two properties of x-rays.

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

Define population inversion and metastable stable.

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

Briefly describe continuous x-rays.

What is fluorescence?

How does a Kax-rays differ KbX-rays?

What is meant by lasing action?

what is Spectroscopy?

What is meant by line spectrum? How line spectrum can be used for the identification of elements?

Define normal population and population inversion.

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

What are the advantages of laser over ordinary light?

Write down use of laser in industry.

ICS Part 2 Physics Chapter 20 Short Questions Preparation

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12th Class Physics
Short Questions Preparation

How does a K_ax-rays differ K_bX-rays?

How does a K_ax-rays differ K_bX-rays?