Question # 1

The minimum wavelength of X-rays produced of 1KV potential difference is applied across the anode and cathode of the tube is

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1.24 x 10^-10m

7.92 x 10^-20m

2.78 x 10^-14m

3.88 x 10^-11m

The He-Ne laser discharge tube is filled with:

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85% He

15% He

50% He

60% He

85% Ne

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

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)

The holes created in the L and M shells are occupied by transitions of:

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Electrons from lower states

Electrons from higher state

Positrons from higher states

Electrons from K shell

Both (A) and (B)

X-ray are also known as

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Roentgen rays

Maxwell rays

Plank range

Einstein rays

Lyman series in the spectrum of hydrogen exists in the :

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Infra-red region

Visible region

Ultraviolet region

Both(A) and (B)

None of these

The transitions of electrons in the hydrogen atom result in the emission of spectral lies in the:

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Ultra red region

Visible region

Ultraviolet region

Any of these

None of these

If the distance between two charges is doubled,the force between them will become:

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Double

Half

One third

One fourth

The range of wavelengths of colurs in the visible colours is

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140 nm to 456 nm

10 nm to 56 nm

410 nm to 656 nm

910 nm to 956 nm

None of these

Graph of Black body radiation is example of

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Band spectra

Continuo's spectra

Line spectra

All

X-rays can penetrate in a solid matte through a distance of several:

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Kilo metres

Metres

Centimeters

A few angstroms

One micrometer

The photocopying process is called:

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Geography

Sonography

Xerography

Zerography

None 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

The first shell near the neucles is

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L-shell

X-shell

N-shell

M-shell

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