ECAT Pre General Science Chapter 20 online mcq test with answers for Physics chapter 20 (Atomic Spectra)

Question # 1

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

Great amount of X-rays to pass A
Smallast amount of X-rays to pass B
Very samall amount of X-rays to pass C
Any of these D
None of these E

Question # 2

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

Ultra red region A
Visible region B
Ultraviolet region C
Any of these D
None of these E

Question # 3

The He-Ne laser discharge tube is filled with:

85% He A
15% He B
50% He C
60% He D
85% Ne E

Question # 4

The natural arrangement of colours in the spectrum of white light spectrum is

VIBGYOR A
ROYBGIV B
ROYBIGV C
BIGROYV D
None of these E

Question # 5

A metastable stae:

Is an excited state A
Is that in which excited electron is stable B
Is that in which excited electron is usually unstable C
Means a time interval of 10^-8second D
Both (A) and (C) E

Question # 6

Graph of Black body radiation is example of

Band spectra A
Continuo's spectra B
Line spectra C
All D

Question # 7

Lyman series in the spectrum of hydrogen exists in the :

Infra-red region A
Visible region B
Ultraviolet region C
Both(A) and (B) D
None of these E

Question # 8

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

Kilo metres A
Metres B
Centimeters C
A few angstroms D
One micrometer E

Question # 9

Tick the series which lies in the visible region:

Lyman series A
Balmer series B
Paschen series C
Brackett series D
P fund series E

Question # 10

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

Pfund series A
Brackett series B
Paschen series C
All of these D
None of these E

Question # 11

The spectrum emitted from hydrogen filled discharge tube is:

Line spectrum A
Discrete spectrum B
And spectrum C
Absorption spectrum D
Both (A) and (B) E

Question # 12

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

Wavelength A
Frequency B
Energy C
Both (A) and (B) D
All of these E

Question # 13

The electric field lines start from:

Positive charge A
Negative charge B
Either A and B C
Neutron D
An atom E

Question # 14

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

Nitrogen A
Helium B
Hydrogen C
Neon D
None of these E

Question # 15

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

Short wavelength A
Large wavelength B
Very large wavelenth C
Low frequency D
Both (B) and (C) E

Question # 16

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

Less than atmospheric pressure A
Much less than atmospheric pressure B
Greater than atmospheric pressure C
Much greater than atmospheric pressure D
Both C and D E

Question # 17

The life time of metastable state is equal to

Life time of excited state A
Greater than by excited state B
Zero C
Less than by excited state D

Question # 18

We can excite an atom by

Bombardment of particles A
Radiating photons B
Providing potential difference C
All answer are true D

Question # 19

The process of formation of spectrum is called:

Interference A
Spectroscopy B
Dispersion C
Reflection D
Botha (A) and (D) E

Question # 20

The range of wavelengths of colurs in the visible colours is

140 nm to 456 nm A
10 nm to 56 nm B
410 nm to 656 nm C
910 nm to 956 nm D
None of these E

Question # 21

Coulomb multiplied by volt by volt gives the unit called:

farad A
Ohm B
Second C
joule D
Watt E

Question # 22

CT scanning is the abbreviated name of

Computed Technology A
Computed Technique B
Computed Technology C
Computerized Technique D

Question # 23

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

Bohr
A
Rydberg B
Planck C
Rutherford D
Coulomb E

Question # 24

X-ray are also known as

Roentgen rays A
Maxwell rays B
Plank range C
Einstein rays D

Question # 25

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

Small A
Greater B
Equal C
Sometimes D

Question # 26

The photocopying process is called:

Geography A
Sonography B
Xerography C
Zerography D
None of these E

Question # 27

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

one
A
two B
three C
four D
five E

Question # 28

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

1% A
20% B
30% C
50% D
70% E

Question # 29

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

Frequency A
Penetrating power B
Energy C
Method of creation D

Question # 30

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

Ionization energy A
Ionization potential B
Excitation energy C
Excitation potential D
None of these E

Sr.#	Question	Answer
1	The He-Ne laser discharge tube is filled with:	A. 85% He B. 15% He C. 50% He D. 60% He
2	Tick the series which lies in the visible region:	A. Lyman series B. Balmer series C. Paschen series D. Brackett series
3	Graph of Black body radiation is example of	A. Band spectra B. Continuo's spectra C. Line spectra D. All
4	X-rays produced in a tube operating at 10⁵V. The speed of X-rays produced is	A. 3 x 10⁸m/s B. 3.1 x 10⁸m/s C. 2.8 x 10⁸m/s D. 1.88 x 10⁸m/s
5	X-rays can penetrate in a solid matte through a distance of several:	A. Kilo metres B. Metres C. Centimeters D. A few angstroms
6	Coulomb multiplied by volt by volt gives the unit called:	A. farad B. Ohm C. Second D. joule
7	The results of spectra obtained by Balmer were expressed in 1896 by:	A. Bohr B. Rydberg C. Planck D. Rutherford
8	The first series which was identified in the spectrum of hydrogen is called:	A. Lyman series B. Balmer series C. Paschen series D. Brackett series
9	The spectrum emitted from hydrogen filled discharge tube is:	A. Line spectrum B. Discrete spectrum C. And spectrum D. Absorption spectrum
10	The photocopying process is called:	A. Geography B. Sonography C. Xerography D. Zerography

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