Question # 1

Balmer series was identified in:

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1685

1785

1885

1985

1585

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

X-ray are also known as

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Roentgen rays

Maxwell rays

Plank range

Einstein rays

In helium Neon Laser Neon = 15% and Helium = 85% used. The lasing gas this unit is

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Helium

Neon

Both

None of these

Gaussian surface is always:

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Rectangular

Spherical

Cylinder

Box shape

Any of these

The value of the metastable state for Neon is

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20.66eV

20.61eV

19.23eV

18.70eV

Laser is a beam of:

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Visible light

Infra red light

Ultra violet light

Violet light only

yellow light only

The first series which was identified in the spectrum of hydrogen is called:

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Lyman series

Balmer series

Paschen series

Brackett series

Pfund series

The He-Ne laser discharge tube is filled with:

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85% He

15% He

50% He

60% He

85% Ne

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)

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

Coulomb multiplied by volt by volt gives the unit called:

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farad

Ohm

Second

joule

Watt

X-rays produced in a tube operating at 10⁵V. The speed of X-rays produced is

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3 x 10⁸m/s

3.1 x 10⁸m/s

2.8 x 10⁸m/s

1.88 x 10⁸m/s

The inkjet printer eject a thin stream of:

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Water

Oil

Ink

Any above

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

The results of spectra obtained by Balmer were expressed in 1896 by:

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Bohr

Rydberg

Planck

Rutherford

Coulomb

Braking radiation causes:

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Continuous spectrum

Line Spectrum

Band spectrum

Discrete specturm

All of these

Photons must have energy equal to

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ev

En

hf

None of these

Spectrum represents the number of component colours present in certain light in terms of:

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Wavelength

Frequency

Energy

Both (A) and (B)

All of these

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 electric field lines start from:

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Positive charge

Negative charge

Either A and B

Neutron

An atom

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)

Balmer series lies in that region of electromagnetic wave spectrum which is called:

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Visible region

Invisible region

Infra-red region

ultraviolet region

None of these

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

The spectrum emitted from hydrogen filled discharge tube is:

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Line spectrum

Discrete spectrum

And spectrum

Absorption spectrum

Both (A) and (B)

The process of formation of spectrum is called:

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Interference

Spectroscopy

Dispersion

Reflection

Botha (A) and (D)

The lasing or active medium in He-Ne laser discharge tube is:

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Nitrogen

Helium

Hydrogen

Neon

None of these

CT scanning is the abbreviated name of

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Computed Technology

Computed Technique

Computed Technology

Computerized Technique

We can excite an atom by

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Bombardment of particles

Radiating photons

Providing potential difference

All answer are true

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

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