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

Question # 1

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 # 2

Balmer series was identified in:

1685 A
1785 B
1885 C
1985 D
1585 E

Question # 3

Static electricity is produced by the transfer of:

Electrons A
Protons B
One fluid C
Two fluid D
None of these E

Question # 4

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 # 5

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

3 x 10⁸m/s A
3.1 x 10⁸m/s B
2.8 x 10⁸m/s C
1.88 x 10⁸m/s D

Question # 6

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

1.24 x 10^-10m A
7.92 x 10^-20m B
2.78 x 10^-14m C
3.88 x 10^-11m D

Question # 7

CT scanning is the abbreviated name of

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

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

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

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

Question # 10

The process of formation of spectrum is called:

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

Question # 11

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 # 12

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 # 13

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 # 14

The shell closer to the nucleus is called:

N shell A
L shell
B
K shell C
M shell D
O shell E

Question # 15

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 # 16

The value of the metastable state for Neon is

20.66eV A
20.61eV B
19.23eV C
18.70eV D

Question # 17

Graph of Black body radiation is example of

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

Question # 18

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

Ground state A
Excited state B
Ionized state C
Any of these D
None of these E

Question # 19

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 # 20

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

Lyman series A
Balmer series B
Paschen series C
Brackett series D
Pfund series E

Question # 21

Photons must have energy equal to

ev A
En B
hf C
None of these D

Question # 22

Braking radiation causes:

Continuous spectrum A
Line Spectrum B
Band spectrum C
Discrete specturm D
All of these E

Question # 23

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

Visible region A
Invisible region B
Infra-red region C
ultraviolet region D
None of these E

Question # 24

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

Question # 25

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

Double A
Half B
One third C
One fourth D

Question # 26

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 # 27

Coulomb multiplied by volt by volt gives the unit called:

farad A
Ohm B
Second C
joule D
Watt E

Question # 28

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

Bohr
A
Rydberg B
Planck C
Rutherford D
Coulomb E

Question # 29

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 # 30

The He-Ne laser discharge tube is filled with:

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

Sr.#	Question	Answer
1	Lyman series in the spectrum of hydrogen exists in the :	A. Infra-red region B. Visible region C. Ultraviolet region D. Both(A) and (B)
2	By CAT scans, we can detect the density difference of the order of:	A. 1% B. 20% C. 30% D. 50%
3	The transitions of electrons in the hydrogen atom result in the emission of spectral lies in the:	A. Ultra red region B. Visible region C. Ultraviolet region D. Any of these
4	X-ray are also known as	A. Roentgen rays B. Maxwell rays C. Plank range D. Einstein rays
5	Tick the series which lies in the visible region:	A. Lyman series B. Balmer series C. Paschen series D. Brackett series
6	The life time of metastable state is equal to	A. Life time of excited state B. Greater than by excited state C. Zero D. Less than by excited state
7	Spectrum represents the number of component colours present in certain light in terms of:	A. Wavelength B. Frequency C. Energy D. Both (A) and (B)
8	The inkjet printer eject a thin stream of:	A. Water B. Oil C. Ink D. Any above
9	The lasing or active medium in He-Ne laser discharge tube is:	A. Nitrogen B. Helium C. Hydrogen D. Neon
10	The formula of Brackett series can be obtained by putting in the general formula, the value of n equal to:	A. one B. two C. three D. four

Latest Educational News Stories

Pakistan's Largest Database of Colleges and Universities

BS Programs

University Past Papers

University Results

Exam Results 2024

Study Abroad Programs and Opportunities for Pakistani Students

ECAT Pre General Science Physics Chapter 20 MCQ Test With Answer

MCQ's Test For ECAT Pre General Science Physics Chapter 20 Atomic Spectra

ECAT Pre General Science Physics Chapter 20 Atomic Spectra