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

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 # 3

What do you mean by inner shell transition?

Ans 1: A transition in which an electron from higher orbit,emits energy and accommodate a hole in the lower orbit.Such a transition is called inner shell transition.The photons emitted in such transition are called characteristic x-rays.

Question # 4

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 # 5

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 # 6

Write two properties of x-rays.

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

Question # 7

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 # 8

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 # 9

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 # 10

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.}

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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?

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

What do you mean by inner shell transition?

Distinguished between stimulated emission and spontaneous emission.

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

Write two properties of x-rays.

What is fluorescence?

Give two uses of laser in medicine and industry.

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

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

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?

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

What do you mean by inner shell transition?

Distinguished between stimulated emission and spontaneous emission.

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

Write two properties of x-rays.

What is fluorescence?

Give two uses of laser in medicine and industry.

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

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

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

What is meant by lasing action?

What do you mean by inner shell transition?

Distinguished between stimulated emission and spontaneous emission.

Write two properties of x-rays.

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

What are the advantages of laser over ordinary light?

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

Give two uses of laser in medicine and industry.

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?

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

Briefly describe continuous x-rays.

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?

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

Write use of x-rays.

Write two properties of x-rays.

How does a Kax-rays differ KbX-rays?

Write down use of laser in industry.

What are the advantages of laser over ordinary light?

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

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?