ICS Part 2 Physics Chapter 19 Short Questions Preparation

Question # 1

Define work function and threshold frequency.

Ans 1: The minimum amount of energy required to remove electrons from a metal surface is called work function of this metal.
The minimum frequency below which photoelectric effect can not occur from a metal surface is called threshold frequency of this metal.

Question # 2

Which has the lower energy quanta,radio waves or x rays?Explain

Ans 1: Energy of quanta is given as E=hf-hc/lamda
Radio waves length has longer wavelength,Therefore radio waves has lower energy quanta.

Question # 3

Distinguished between photoelectric effect and Compton effect.

Ans 1: The emission of electron from a metal surface when exposed to suitable frequency light is called photoelectric effect and when x rays are scattered by loosely bound electrons from graphite target the phenomena of change in wavelength is known as compton effect.

Question # 4

Differentiate between special theory of relativity and general theory of relativity.

Ans 1: The special theory of relativity treats problem involving inertial or non accelerating frame of reference.
Ans 2: The general theory of relativity treats problem involving frames of reference accelerating with respect to one another.

Question # 5

Why don't we observe a Compton Effect with visible light?

Ans 1: The frequency of visible light is less than x rays,And the wavelength of visible light is much greater than the Compton of wavelength of electron,So compton effect can not observed with visible light.

Question # 6

State uncertainty principle.

Ans 1: The product of uncertainty in the measurement of momentum and uncertainty in the measurement of position of an electron is approximately equal to Planck's constant.
The product of uncertainty in the measurement of energy and uncertainty in the measurement of time of an electron is approximately equal to Planck's constant.

Question # 7

Define Compton effect.Write formula of Compton shift for scattering angle.

Ans 1: When X-rays are scattered by loosely bound electrons from a graphite target,the phenomena of change in wavelength is known as Compton Effect.Compton shift for scattering angle is given
$\lambda '-\lambda ={\frac {h}{m_{e}c}}(1-\cos {\theta }),$

Question # 8

Photoelectric effect give the evidence of the particle nature of light,Explain it how?

Ans 1: If light were simple a wave like phenomena ,then increasing the intensity and thereby increasing the total energy failing on the surface would be expected to eventually provide enough energy to release electron no matter what the frequency .Furthermore in the classical picture one would expect the maximum energy of the emitted electrons to depend on the intensity of light--but it does not.So this is evidence that light behaves as if it were a particle.

Question # 9

Why can red light be used in a photographic dark room when developing films,but a blue or white light can not?

Ans 1: As we known red light has longest wavelength in visible spectrum,therefore it has less energy than that of blue or white light.So red light is least scattered on account of its large wavelength.Hence photographic films and the materials concerned are less affected in the presence of red light than high energy blue of white light.

Question # 10

When does light behaves as a wave?When does light behaves as a particle?

Ans 1: Light behave as a wave when it propagates from one place to other and light behave as a particle when it interacts with matter,Light behaves as a wave in interference and diffraction,Light behaves as a particle in photoelectric and Compton effect.

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ICS Part 2 Physics Chapter 19 Short Questions Preparation

12th Class PhysicsShort Questions Preparation

12th Class Physics Chapter Wise Preparation

Online Short Questions For Chapter 8 "ICS Part 2 Physics Chapter 19 Short Questions Preparation "

Physics - ICS Part 2 Physics Chapter 19 Short Questions Preparation

Define work function and threshold frequency.

Which has the lower energy quanta,radio waves or x rays?Explain

Distinguished between photoelectric effect and Compton effect.

Differentiate between special theory of relativity and general theory of relativity.

Why don't we observe a Compton Effect with visible light?

State uncertainty principle.

Define Compton effect.Write formula of Compton shift for scattering angle.

Photoelectric effect give the evidence of the particle nature of light,Explain it how?

Why can red light be used in a photographic dark room when developing films,but a blue or white light can not?

When does light behaves as a wave?When does light behaves as a particle?

Prepare Complete Set Wise Questions For Chapter 8 "ICS Part 2 Physics Chapter 19 Short Questions Preparation "

Set 1

Set 2

Set 3

ICS Part 2 Physics Chapter 19 Short Questions Preparation - Set 1

Define work function and threshold frequency.

Which has the lower energy quanta,radio waves or x rays?Explain

Distinguished between photoelectric effect and Compton effect.

Differentiate between special theory of relativity and general theory of relativity.

Why don't we observe a Compton Effect with visible light?

State uncertainty principle.

Define Compton effect.Write formula of Compton shift for scattering angle.

Photoelectric effect give the evidence of the particle nature of light,Explain it how?

Why can red light be used in a photographic dark room when developing films,but a blue or white light can not?

When does light behaves as a wave?When does light behaves as a particle?

ICS Part 2 Physics Chapter 19 Short Questions Preparation - Set 2

Give two postulate of special theory of relativity.

Define Stopping potential and Threshold frequency.

Which has the lower energy quanta,radio waves or x rays?Explain

What are conclusion made from the pair production?

As a solid is heated and begins to glow ,why does it first of its absolute.

Will the bright light ejects more from metal surface than dimmer light of tha same colour?

Define ionization potential and excitation potential.

When does light behaves as a wave?When does light behaves as a particle?

Define pair production and annihilation of matter.

A satellite is orbiting around earth.Is its frame of reference inertial or non-inertial ?Justify your answer.

ICS Part 2 Physics Chapter 19 Short Questions Preparation - Set 3

Why can red light be used in a photographic dark room when developing films,but a blue or white light can not?

What is wave particle duality?

What are the measurement on which two observers in relative motion will always agree upon?

What are conclusion made from the pair production?

State uncertainty principle.

As a solid is heated and begins to glow ,why does it first of its absolute.

What advantage of an electron microscope has over an optical microscope?

Will higher frequency of light ejects greater number of electrons than low frequency of light?

Can an object move with the speed of light?

Define Stopping potential and Threshold frequency.

ICS Part 2 Physics Chapter 19 Short Questions Preparation

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