Question # 1

When low energy photon interact with a metal,which of the following effect is likely to be taken place

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pair production

photoelectric

Compton effect

None of these

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.

The unit of work function is:

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Joule

Electron volt

That of threshold frequency

Both (A) and (B)

None of these

According to the Max plank, energy is redialed or absorbed in

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discrete packets

continuous waves

either of them

none of these

Which one of the following physical quantities changes with relativistic speed

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Length

Mass

Time

All of the above

When platinum wire is heated, it appears cherry red at

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1600°C

900°C

1100°C

1300°C

The energy of a photon in a beam of infrared radiation of wavelength 1240 nm is

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100 ev

10⁶e v

10³e v

1.0 e v

When platinum wire is heated, then at the temperature of 500 ^oC, it becomes:

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Yellow

Orange red

Dull red

White

Cherry red

Compton was awarded Nobel prize in physics in

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1921

1923

1925

1927

The special theory of relativity is based on the

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one postulate

two postulates

three postulates

four postulates

At the temperature, a body emits radiation which is principally

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of long wavelengths in the visible region

of long wavelengths in the invisible infrared region

of short wavelength in invisible ultraviolet region

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

The whole shape of the black body spectrum for all wavelengths was explained by the formula proposed by

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Max plank

Newton

Einstein

J.J. Thomson

The idea of quantization of energy was proposed by:

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Einstein

Max.Planck

Maxwell

Bohr

Rutherford

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

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