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

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

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 # 5

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 # 6

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 # 7

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.

Question # 8

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 # 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

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.

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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?

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?

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

What is CAT scanner?

What is fluorescence?

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

Distinguished between stimulated emission and spontaneous emission.

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?

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?

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

What is CAT scanner?

What is fluorescence?

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

Distinguished between stimulated emission and spontaneous emission.

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

How does a Kax-rays differ KbX-rays?

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

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

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 we mean when we say that the atom is excited?

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

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

What are the advantages of laser over ordinary light?

Define continuous spectrum.

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

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

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

Differentiate between Line and Band spectrum.

What do you mean by inner shell transition?

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

Can electron reside inside the nucleus?

Write use of x-rays.

Write two properties of x-rays.

Define normal population and population inversion.

what is Spectroscopy?

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?