ICS Part 2 Physics Chapter 20 Short Questions Preparation

Question # 1

Briefly describe continuous x-rays.

Ans 1: Continuous X-rays is due to an effect known as Bremsstrahlung effect when fast moving electron bombarded at the target,they are suddenly slowed down on impact with the target,And due to deceleration their kinetic energy is converted into X-rays photons.

Question # 2

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 # 3

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 # 4

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

Ans 1:
- An electron ,bound to the nucleus in an atom,can moved around the nucleus in certain circular orbits without radiating,These orbits are called the discrete stationary orbits.
- Only those stationary orbits are allowed for which orbital angular momentum is equal to an integral multiple mvr=nh/2π.

Question # 5

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 # 6

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 # 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

What are the advantages of laser over ordinary light?

Ans 1: Laser light has many advantages over ordinary light such as laser light is
1. Coherent
2. Intense
3. Monochromatic
4. Unidirectional

Question # 9

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 # 10

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

Ans 1: When energy from some external source is provide to an atom in its normal state,then its electron will jump from lower energy state to higher energy state.And atom is said to be excited.

Latest Educational News Stories

Pakistan's Largest Database of Colleges and Universities

BS Programs

University Past Papers

University Results

Exam Results 2024

Study Abroad Programs and Opportunities for Pakistani Students

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

Briefly describe continuous x-rays.

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.

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

Define continuous spectrum.

Distinguished between stimulated emission and spontaneous emission.

What is fluorescence?

What are the advantages of laser over ordinary light?

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

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

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

Briefly describe continuous x-rays.

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.

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

Define continuous spectrum.

Distinguished between stimulated emission and spontaneous emission.

What is fluorescence?

What are the advantages of laser over ordinary light?

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

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

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

Define normal population and population inversion.

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

What do you mean by inner shell transition?

Differentiate between Line and Band spectrum.

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

Give two uses of laser in medicine and industry.

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

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

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

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

What are the advantages of laser over ordinary light?

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

Write use of x-rays.

Give two uses of laser in medicine and industry.

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

Can electron reside inside the nucleus?

Write down use of laser in industry.

What is fluorescence?

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

What are the difference between laser light and ordinary light?

ICS Part 2 Physics Chapter 20 Short Questions Preparation

Is this page helpful?

12th Class Physics
Short Questions Preparation