Question # 1

Photoelectrons are emitted when ultraviolet light falls on:

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Casium

Silver

Potassium

Any of these

None of these

According to Einstein, with the great increase in the speed of the body, the relativistic mass of the body

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Remains constant

Decreases

Increases to infinity

Reduced to zero

A photon is considered to have

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Momentum

Energy

Wavelength

All of the above

The analysis of the distribution of wavelengths of the radiation emitted from a hot body set the foundation of new mechanics, known as

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classical mechanics

Newtonian mechanics

quantum mechanics

statistical mechanics

When the atomic particle are moving with velocities approaching that of light:

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Newton's laws become valid

Relativistic effects become prominent

Botha(A) and (B) are valid

Neither (A)nor (B)

There mass becomes zero.

In order to produce pair production, a photon must have a energy

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0.511 Me v

0.256 Me v

1.02 Me v

0.956 Me v

Absolute motion cannot be detected

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in its own frame of references

in a different frame of references

both in its frame and different frame of references

none of these

The length contraction happens only

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Opposite to the direction of motion

along the direction of motion

perpendicular to the direction of motion

In any direction

Wave nature of particle was proposed by

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Einstein

Plank

De-Brogile

Max well

A particle having mass and charge equal to that of an electron is called:

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Proton

Positron

Pion

Pi-meson

Both (C) and (D)

Intensity of light determines the:

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Energy of each photon

Number of photons

Speed of photons

Size of photons

None of these

Which of the following phenomenon proves the particle nature of light

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interference

diffraction

photoelectric effect

none of these

According to the special theory of relativity, a moving clock

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runs faster

runs slower

neither runs faster nor slower

all of these

If A represents linear momentum and c, the velocity of light, then unit of pc in international system of units is:

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Newton

Joule

Joule-Sec

Joule-s^-1

Watt

According to Einstein, with the great increase in the speed of the body the relativistic length of the body

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Remains constant

Decreases

Increases

Reduces to zero

Max plank received the Nobel Prize in physics for his discovery of energy quanta in

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1900

1906

1912

1918

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ECAT Physics Chapter 19 Dawn of Modern Physics Online Test MCQs With Answers

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