ICS Part 2 Physics Chapter 19 Short Questions Preparation

Question # 1

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 # 2

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 # 3

What are black body radiations and how can you get a black body?

Ans 1: An objects that absorbs all radiations falling on it,at all wavelength is called a black body.
When a body is heated ,it emits radiation its emission is called black body.
Black body is solid that has hollow cavity within it and a small hole through which radiations can enter or escape.The inside is blackened with suit to make it as good an absorber and as a bad reflector as possible.

Question # 4

What do you understand by work function and stopping potential?

Ans 1: The minimum amount energy required to remove an electron from the surface of a metal is called work function.
And the stopping potential is the potential difference applied to stop the electrons from being ejected from the surface when the light falls on it.

Question # 5

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 # 6

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 # 7

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.

Question # 8

What are advantages of NAVSTAR navigation system?

Ans 1: NAVSTAR is used to locate the position and find the speed of an object anywhere on Earth up to to an accuracy of 2 cms^-1.

Question # 9

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 # 10

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.

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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

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

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

What are black body radiations and how can you get a black body?

What do you understand by work function and stopping potential?

Define ionization potential and excitation potential.

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

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

What are advantages of NAVSTAR navigation system?

What do you know by annihilation of matter?

Define Stopping potential and Threshold frequency.

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

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

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

What are black body radiations and how can you get a black body?

What do you understand by work function and stopping potential?

Define ionization potential and excitation potential.

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

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

What are advantages of NAVSTAR navigation system?

What do you know by annihilation of matter?

Define Stopping potential and Threshold frequency.

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

Can an object move with the speed of light?

Define Compton effect.

When light shine on surface,is momentum transferred to metal surface?

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

Differentiate between inertial and non-inertial frame of reference.

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

Give two postulate of special theory of relativity.

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

What is wave particle duality?

What are black body radiations and how can you get a black body?

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

What are conclusion made from the pair production?

What do you know by annihilation of matter?

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

λ =h/mv

Can a pair production take place in vacuum?Explain

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?

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

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

What do you understand by work function and stopping potential?

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

ICS Part 2 Physics Chapter 19 Short Questions Preparation

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