ICS Part 2 Physics Chapter 20 Short Questions Preparation

Question # 1

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 # 2

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 # 3

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 # 4

Write two properties of x-rays.

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

Question # 5

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 # 6

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 # 7

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 # 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

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 # 10

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.

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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

Distinguished between stimulated emission and spontaneous emission.

Differentiate between Line and Band spectrum.

Define normal population and population inversion.

Write two properties of x-rays.

What is CAT scanner?

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

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

Write use of x-rays.

Give two uses of laser in medicine and industry.

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

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

Distinguished between stimulated emission and spontaneous emission.

Differentiate between Line and Band spectrum.

Define normal population and population inversion.

Write two properties of x-rays.

What is CAT scanner?

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

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

Write use of x-rays.

Give two uses of laser in medicine and industry.

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

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

Write down use of laser in industry.

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

What are the difference between laser light and ordinary light?

Give two uses of laser in medicine and industry.

Write two properties of x-rays.

Define normal population and population inversion.

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

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

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

Differentiate between Line and Band spectrum.

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

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

Briefly describe continuous x-rays.

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?

What are the difference between laser light and ordinary light?

Can electron reside inside the nucleus?

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

Define population inversion and metastable stable.

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

How does a Kax-rays differ KbX-rays?

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?