ICS Part 2 Physics Chapter 19 Short Questions Preparation

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Short Questions Preparation

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

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Physics - ICS Part 2 Physics Chapter 19 Short Questions Preparation

Question # 1

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

Ans 1: No it will not,The number of ejected electrons depend upon the intensity of light.They are independently of frequency.

Question # 2

Define ionization potential and excitation potential.

Ans 1: Ionization potential:The potential necessary to remove an electron from the atom is called ionization potential,It is expressed in volts.
Ans 2: Excitation potential:The potential require to raise orbital electron in atom from one energy level to an other is called excitation potential.

Question # 3

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 # 4

Can a pair production take place in vacuum?Explain

Ans 1: No,pair production can not take place in vacuum.
In order to conserve the momentum and energy,their presence of heavy nucleus is essential,The vacuum has no particle or heavy nucleus,Therefore pair production can not take place in vacuum.

Question # 5

Define Stopping potential and Threshold frequency.

Ans 1: Stopping potential:The stopping potential is the potential difference applied to stop the electrons from being ejected from the surface when the light fall on it.
Threshold frequency:The minimum of frequency of incident light at which electrons are emitted from a surface is called threshold frequency.

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

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.

Question # 8

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

Ans 1: Since intensitynumber of electrons.
and bright lightis more intensethan dimmer one.So bright light will ejects more electrons than dimmer light.

Question # 9

We do not notice the de-Broglie wavelength for a pitched cricket ball.Explain why?

Ans 1: According to de-Broglie hypothesis
λ =h/mv
As cricket ball has large mass,therefore wavelength of wavelength associated with it is so small that is not detectable.

Question # 10

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.

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

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Set 2

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Set 3

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

Question # 1

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

Ans 1: No it will not,The number of ejected electrons depend upon the intensity of light.They are independently of frequency.

Question # 2

Define ionization potential and excitation potential.

Ans 1: Ionization potential:The potential necessary to remove an electron from the atom is called ionization potential,It is expressed in volts.
Ans 2: Excitation potential:The potential require to raise orbital electron in atom from one energy level to an other is called excitation potential.

Question # 3

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 # 4

Can a pair production take place in vacuum?Explain

Ans 1: No,pair production can not take place in vacuum.
In order to conserve the momentum and energy,their presence of heavy nucleus is essential,The vacuum has no particle or heavy nucleus,Therefore pair production can not take place in vacuum.

Question # 5

Define Stopping potential and Threshold frequency.

Ans 1: Stopping potential:The stopping potential is the potential difference applied to stop the electrons from being ejected from the surface when the light fall on it.
Threshold frequency:The minimum of frequency of incident light at which electrons are emitted from a surface is called threshold frequency.

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

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.

Question # 8

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

Ans 1: Since intensitynumber of electrons.
and bright lightis more intensethan dimmer one.So bright light will ejects more electrons than dimmer light.

Question # 9

We do not notice the de-Broglie wavelength for a pitched cricket ball.Explain why?

Ans 1: According to de-Broglie hypothesis
λ =h/mv
As cricket ball has large mass,therefore wavelength of wavelength associated with it is so small that is not detectable.

Question # 10

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.

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

Question # 1

Define Compton effect.

Ans 1: The phenomena of increase in wavelength of x rays photon scattered by loosely bound electrons from a graphite target is called Compton Effect.

Question # 2

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 # 3

Define Stopping potential and Threshold frequency.

Ans 1: Stopping potential:The stopping potential is the potential difference applied to stop the electrons from being ejected from the surface when the light fall on it.
Threshold frequency:The minimum of frequency of incident light at which electrons are emitted from a surface is called threshold frequency.

Question # 4

Define ionization potential and excitation potential.

Ans 1: Ionization potential:The potential necessary to remove an electron from the atom is called ionization potential,It is expressed in volts.
Ans 2: Excitation potential:The potential require to raise orbital electron in atom from one energy level to an other is called excitation potential.

Question # 5

What do you know by annihilation of matter?

Ans 1: When a positron comes close to an electron,they annihilate and produce two photons in the gamma rays range.It is called annihilation of matter.

Question # 6

The rest mass of photon is zero.Is its momentum also zero?

Ans 1: No,The rest mass of photon is zero.It travels in the form of small energy packets which are of equal wavelength .When it is in motion,it possesses some mass.So it which it will also have momentum.

Question # 7

Is it possible to create a single electron from energy?

Ans 1: No it is not possible to create single electron from energy.Because electron has negative charge and photon has no charge,

Question # 8

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

Ans 1: No it will not,The number of ejected electrons depend upon the intensity of light.They are independently of frequency.

Question # 9

Write at least two justification for light to behave as wave and as a particle.

Ans 1: Interference and diffraction confirms wave nature of light while photoelectric effect and compton effect confirms particle nature of light.

Question # 10

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.

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

Question # 1

What are conclusion made from the pair production?

Ans 1: Pair production is the creation of an elementary particle and its antiparticle,Pair production offers refers specifically to a photon creating an electron positron pair near a nucleus but can more generally refer to any particle antiparticle pair creation.
Energy can be converted into mass according to E=mc²

Question # 2

Define pair production and annihilation of matter.

Ans 1: Pair production:The change of very high energy photon into an electron,positron pair is called pair production.
Annihilation of matter:When a positron comes close to an electron,they annihilation and produce two photons in the gamma rays range.It is called annihilation of matter.

Question # 3

Can an object move with the speed of light?

Ans 1: As an object approaches the speed of light,its masses rises abruptly.If an object tries to travel 186,000 miles per seconds,its mass become infinite and so does the energy required to move it, For this reasons ,no normal object can be travel as fast as or faster than the speed of light.

Question # 4

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

Ans 1: The motion of the satellite is synchronized with the earth so it is in the same frame of reference in which earth lies.Hence the frame of reference will be inertial.

Question # 5

What is wave particle duality?

Ans 1: It says that light has dual nature;it travels in the form of waves but interacts with matter in the form of energy particle called as photon.e.g in interference ,reflection and polarization it show the properties of wave nature but in phenomena like pair production and compton's effect light acts as energy particle.

Question # 6

Can a pair production take place in vacuum?Explain

Ans 1: No,pair production can not take place in vacuum.
In order to conserve the momentum and energy,their presence of heavy nucleus is essential,The vacuum has no particle or heavy nucleus,Therefore pair production can not take place in vacuum.

Question # 7

If you are moving in a spaceship at very high speed relative to the earth.Would you notice difference(a)In your pulse rate(b)In the pulse rate of people on the earth?

Ans 1:
1. The pulse rate of the person inside the spaceship moving with large velociety will decrease.
2. The pulse rate of the people on the earth with respect to the person inside the spaceship with large velocity will increase.

Question # 8

Is it possible to create a single electron from energy?Explain

Ans 1: No it is not possible to create a single electron from energy.Creation of single electron will be against the law of conservation of charge and the law of conservation of momenteum.In pair production an electron positron pair is produces.

Question # 9

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 # 10

Does the dilation mean that time really passes more slowly in moving system or that it only seems to pass more slowly.Explain briefly.

Ans 1: According to dilation formula
t= $\scriptstyle {\sqrt {1-{\frac {v^{2}}{c^{2}}}}}$ "
This relation show that a clock moving with respect to an observe appears to move slow then it does when it is at rest with respecttohim.So the moving clocks just appears to run slowly to the observer at rest.Hence time dilation is an apparent change and it only seems to pass more slowly but not actually.

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ICS Part 2 Physics Chapter 19 Short Questions Preparation

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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

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

Define ionization potential and excitation potential.

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

Can a pair production take place in vacuum?Explain

Define Stopping potential and Threshold frequency.

State uncertainty principle.

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

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

We do not notice the de-Broglie wavelength for a pitched cricket ball.Explain why?

λ =h/mv

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

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

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

Define ionization potential and excitation potential.

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

Can a pair production take place in vacuum?Explain

Define Stopping potential and Threshold frequency.

State uncertainty principle.

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

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

We do not notice the de-Broglie wavelength for a pitched cricket ball.Explain why?

λ =h/mv

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

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

Define Compton effect.

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

Define Stopping potential and Threshold frequency.

Define ionization potential and excitation potential.

What do you know by annihilation of matter?

The rest mass of photon is zero.Is its momentum also zero?

Is it possible to create a single electron from energy?

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

Write at least two justification for light to behave as wave and as a particle.

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

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

What are conclusion made from the pair production?

Define pair production and annihilation of matter.

Can an object move with the speed of light?

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

What is wave particle duality?

Can a pair production take place in vacuum?Explain

If you are moving in a spaceship at very high speed relative to the earth.Would you notice difference(a)In your pulse rate(b)In the pulse rate of people on the earth?

Is it possible to create a single electron from energy?Explain

State uncertainty principle.

Does the dilation mean that time really passes more slowly in moving system or that it only seems to pass more slowly.Explain briefly.

ICS Part 2 Physics Chapter 19 Short Questions Preparation

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12th Class Physics
Short Questions Preparation