Question # 1

Minimum energy needed to escape an electron ofrm metal surface is called:

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Threshold energy

Threshold frequency

Work function

Work ability

The quantity/factor h/m_oc has the dimensions of.

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Length

Time

Mass

Energy

In the equation if f₂ > then

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An electron miroscope emplys which to one of the following particles?

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Electron ahve a wave nature

Electrons can be focused by an electric field

Electrons can be focused by a magnetic field

All of the above

Application of wave like nature of particle is

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Photodiode

Optical microscope

Electron microscope

Compound microscope

Antiparticle of electron is.

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proton

Photon

Positron

Neutron

The value of Wien's constant:

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2.9x10^-3mk

2.19x10^-7mk

3.18 x10⁶ km^-1

6.21 x 10^-9m²wk³

The minimum frequency needed to emit an electron form metal surface is called:

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Work function

Threshold frequency

Quanta frequency

All of above

If an object moves with speed of light, its mass will be.

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Zero

Maximum

Minimum

infinity

Which one of the following physical quantities change with relativistic speed?

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Length

Time

Mass

All of above

Wave nature of light appears in

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Pair production

Compton effect

Photo electric

Interference

Potassium Cathodes in photocell emit electrons for a light.

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Visible

Infra red

Ultra violet

X rays

Which one of the following paved the way for modern physics

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Newtonian mechanics

Theory of relativity

Quantum theory

All of above

Wave nature of particle was given by:

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Clemensen

Louis de Broglie

Laster H. Germer

Clinton S. Davisson

Light of 4.5 eV is incident on a Cesium surface and stopping potential is 0.25 eV, maximum K.E. of emitted electron is.

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4.5 eV

4.25 eV

4.75 eV

0.25 eV

Compton's effect is associated with

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gamma rays

Beta rays

X rays

Positive rays

De-Broglie waves are associated with

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Moving charged particles only

Moving neutral particles only

All moving particles

All parties whether in motion or at rest

The emission of electrons from metal surface when exposed to light is called:

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Compton effect

Pair production

Photoelectric effect

None of above

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Physics FSC Part 2 Chapter 19 Online MCQ's Test MCQs With Answers

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