Question # 1

Gaussian surface is always:

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Rectangular

Spherical

Cylinder

Box shape

Any of these

An electron of the hydrogen atom in the second orbit is called its:

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Ground state

Excited state

Ionized state

Any of these

None of these

Consider a photon of continuous X-ray and a photon of characteristics X-ray of same wavelength. Which of the following is/are different for the two photons

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Frequency

Penetrating power

Energy

Method of creation

The formula of Brackett series can be obtained by putting in the general formula, the value of n equal to:

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one

two

three

four

five

In flesh, light element like carbon, hydrogen and oxygen predominate. Three elements allows ______ amount of incident X-ray to pass through them

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Small

Greater

Equal

Sometimes

The results of spectra obtained by Blamer were expressed in 1896 by

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Bohr

Rydberg

Planck

Rutherford

Coulomb

The life time of metastable state is equal to

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Life time of excited state

Greater than by excited state

Zero

Less than by excited state

Photons must have energy equal to

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ev

En

hf

None of these

By CAT scans, we can detect the density difference of the order of:

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1%

20%

30%

50%

70%

X-ray are also known as

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Roentgen rays

Maxwell rays

Plank range

Einstein rays

The electric field lines start from:

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Positive charge

Negative charge

Either A and B

Neutron

An atom

Braking radiation causes:

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Continuous spectrum

Line Spectrum

Band spectrum

Discrete specturm

All of these

The inkjet printer eject a thin stream of:

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Water

Oil

Ink

Any above

None of these

Tick the series which lie/s in. the infra-red region.

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Pfund series

Brackett series

Paschen series

All of these

None of these

Atoms of hydrogen gas can be excited by passing electric current through it when the gas is filled into the discharge tube at a pressure which is

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Less than atmospheric pressure

Much less than atmospheric pressure

Greater than atmospheric pressure

Much greater than atmospheric pressure

Both C and D

The value of the metastable state for Neon is

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20.66eV

20.61eV

19.23eV

18.70eV

Balmer series was identified in:

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1685

1785

1885

1985

1585

An compared to solid matter, a crack or an air bubble allows:

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Great amount of X-rays to pass

Smallast amount of X-rays to pass

Very samall amount of X-rays to pass

Any of these

None of these

Selenium is:

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An insulator

A conductor

Both A and B

Excellent conductor

None of these

Laser is a beam of:

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Visible light

Infra red light

Ultra violet light

Violet light only

yellow light only

A metastable stae:

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Is an excited state

Is that in which excited electron is stable

Is that in which excited electron is usually unstable

Means a time interval of 10^-8second

Both (A) and (C)

Energy required by an electron revolving in certain orbit to jump to an excited state is called:

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Ionization energy

Ionization potential

Excitation energy

Excitation potential

None of these

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