Question # 1

X-ray are also known as

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Roentgen rays

Maxwell rays

Plank range

Einstein rays

Ultraviolet region lies in ______ series

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Layman

Balmer

P fund

B racket

Gaussian surface is always:

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Rectangular

Spherical

Cylinder

Box shape

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

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Bohr

Rydberg

Planck

Rutherford

Coulomb

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)

Tick the series which lies in the visible region:

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Lyman series

Balmer series

Paschen series

Brackett series

P fund series

In case of braking radiations, when the rate of deceleration is very large, the emitted radiation corresponds to:

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Short wavelength

Large wavelength

Very large wavelenth

Low frequency

Both (B) and (C)

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 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

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

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

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

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)

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ECAT Physics Chapter 20 Atomic Spectra Online Test MCQs With Answers

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