ICS Part 2 Physics Chapter 20 Short Questions Preparation

Question # 1

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 # 2

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 # 3

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 # 4

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 # 5

Write two properties of x-rays.

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

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

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

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 # 9

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 # 10

What is CAT scanner?

Ans 1: A vastly improved x-rays technique is computerized axial tomography: the corresponding instrument is called CAT scanner.In CAT scanning a number of different orientations.Computer is attached to construct picture,Density difference of the order of one percent can be detected,Tumors and other anomalies much too small to be seen with older techniques can be detected.

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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

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

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

Distinguished between stimulated emission and spontaneous emission.

How does a Kax-rays differ KbX-rays?

Write two properties of x-rays.

Define population inversion and metastable stable.

Define normal population and population inversion.

What are the difference between laser light and ordinary light?

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

What is CAT scanner?

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

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

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

Distinguished between stimulated emission and spontaneous emission.

How does a Kax-rays differ KbX-rays?

Write two properties of x-rays.

Define population inversion and metastable stable.

Define normal population and population inversion.

What are the difference between laser light and ordinary light?

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

What is CAT scanner?

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

Define population inversion and metastable stable.

What is meant by lasing action?

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

what is Spectroscopy?

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

What is fluorescence?

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

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

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

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

Give two uses of laser in medicine and industry.

Define population inversion and metastable stable.

what is Spectroscopy?

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

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

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

What do you mean by inner shell transition?

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

What are the difference between laser light and ordinary light?

Distinguished between stimulated emission and spontaneous emission.

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?