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

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

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 # 4

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 # 5

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 # 6

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 # 7

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 # 8

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 # 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

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

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.

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

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

Give two uses of laser in medicine and industry.

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

Define normal population and population inversion.

what is Spectroscopy?

Define continuous spectrum.

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

Define characteristics of X-rays and continuous 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

Distinguished between stimulated emission and spontaneous emission.

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

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

Give two uses of laser in medicine and industry.

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

Define normal population and population inversion.

what is Spectroscopy?

Define continuous spectrum.

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

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

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

Give two uses of laser in medicine and industry.

Can electron reside inside the nucleus?

How does a Kax-rays differ KbX-rays?

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

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?

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

what is Spectroscopy?

What is fluorescence?

What do you mean by inner shell transition?

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

Write down use of laser in industry.

Give two uses of laser in medicine and industry.

What are the difference between laser light and ordinary light?

What are the advantages of laser over ordinary light?

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

Distinguished between stimulated emission and spontaneous emission.

what is Spectroscopy?

What is CAT scanner?

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

What do you mean by inner shell transition?

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?