Electron cannot exist in the nucleus it is confirmed by observing that

Its size as compare to proton and neutron is very small.

No antiparticle of electron is present.

The velocity of electron must be very high according to uncertainty principle.

Hydrogen atom does not emit X-rays because

Its energy levels are too close to each other

Its energy levels are too far apart

UV radiation can be produced by

Electron excitation in the gas.

Wave-like characteristic of electron is demonstrated by

Diffraction by crystalline solids.

When we excite some atoms by heat collision or electrical discharge they will

Emit either invisible or visible light

Radiate electromagnetic energy with a continuous distribution of wavelength

Absorb particular wavelengths when white light is incident on them

Radiate electromagnetic energy of discrete characteristic wavelength

Emit either invisible or visible light

When X-rays are passed through successive aluminum sheets what happens to their thickness?

Sometimes increases and sometimes decreases

X-rays are diffracted by a crystal but not by a diffraction grating because

The ions in a crystal are well arranged.

The lines in a diffraction grating cannot reflect X-rays.

The penetration power of X-rays is high in a diffraction grating.

The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal

Reflecting mirrors in laser is used to

For producing more energetic lasers.

The characteristic X-rays spectrum is due to

The absorption of ? radiation by the target metal.

The illumination of the target metal by ultra-violet radiation.

The bombardment of the target by protons.

The bombardment of target by electrons.

The absorption of ? radiation by the target metal.

The minimum wavelength of X-rays can further be reduced by

Reducing the pressure or cooling the target.

Increasing the temperature of the filament.

Using a target element of higher atomic number.

Increasing the potential difference between the cathode and the target.

The velocity of laser light is

Different for different colours or frequency.

Maximum frequency in the spectrum from X-ray tube is directly proportional to the

The soft target which can easily emit electrons.

Number of incident electron i.e. filament current.

The kinetic energy of the incident electron i.e. the potential difference through which they are accelerated.

The soft target which can easily emit electrons.

39 + Mcqs in Atomic Spectra Mcqs in Physics Page 1 McqOptions

1.	Bracket series is obtained when all transition of electron terminate on
A.	4th orbit
B.	5th orbit
C.	3rd orbit
D.	2nd orbit
Answer» B. 5th orbit

Discussion

2.	Electron cannot exist in the nucleus it is confirmed by observing that
A.	It does emit ?-radiation.
B.	Its size as compare to proton and neutron is very small.
C.	No antiparticle of electron is present.
D.	The velocity of electron must be very high according to uncertainty principle.
Answer» E.

Discussion

3.	In an electronic transition atom cannot emit
A.	?-rays
B.	Infra red radiation
C.	Visible light
D.	Ultraviolet rays
Answer» B. Infra red radiation

Discussion

4.	Excited atoms return to their ground state in
A.	10-10s
B.	10-8s
C.	10-6s
D.	10-9s
Answer» C. 10-6s

Discussion

5.	Hydrogen atom does not emit X-rays because
A.	Its energy levels are too close to each other
B.	Its energy levels are too far apart
C.	It is too small in size
D.	It has a single electron
Answer» E.

Discussion

6.	Ground state energy of the 4th orbit in a H-atom is
A.	?13.60 eV
B.	?3.40 eV
C.	?0.85 eV
D.	?1.51 eV
Answer» D. ?1.51 eV

Discussion

7.	In an X-ray tube electrons each of charge e are accelerated through V potential difference allowed to hit a metal target. The wavelength of the X-rays emitted is
A.	He/ev
B.	He/Vc
C.	EV/h
D.	Impossible to predict
Answer» B. He/Vc

Discussion

8.	Total number of series in hydrogen spectrum is
A.	Three
B.	Four
C.	Five
D.	Six
Answer» D. Six

Discussion

9.	UV radiation can be produced by
A.	Heating the filament.
B.	Electron excitation in the gas.
C.	Ionization of atoms.
D.	All the above.
Answer» C. Ionization of atoms.

Discussion

10.	Wave-like characteristic of electron is demonstrated by
A.	Line spectrum of atoms.
B.	Production of x-rays.
C.	Diffraction by crystalline solids.
D.	Photoelectric effect.
Answer» D. Photoelectric effect.

Discussion

11.	What is the velocity of a particle of mass m & de-Broglie wavelength ??
A.	H/m?
B.	2h/m?
C.	Mh/h
D.	(2hc/m?)1/2
Answer» B. 2h/m?

Discussion

12.	When we excite some atoms by heat collision or electrical discharge they will
A.	Radiate electromagnetic energy with a continuous distribution of wavelength
B.	Absorb particular wavelengths when white light is incident on them
C.	Radiate electromagnetic energy of discrete characteristic wavelength
D.	Emit either invisible or visible light
Answer» D. Emit either invisible or visible light

Discussion

13.	When X-rays are passed through successive aluminum sheets what happens to their thickness?
A.	Increases
B.	It decreases
C.	It remains same
D.	Sometimes increases and sometimes decreases
Answer» D. Sometimes increases and sometimes decreases

Discussion

14.	Which one of following postulate is in accordance with the Rutherfords model?
A.	Continuous spectra for atoms
B.	Discrete spectra for atoms
C.	Either continuous nor discrete
D.	No spectrum
Answer» B. Discrete spectra for atoms

Discussion

15.	X-ray are
A.	Of unknown nature
B.	High energy electrons
C.	High energy photons
D.	Radio isotopes
Answer» D. Radio isotopes

Discussion

16.	X-rays are diffracted by a crystal but not by a diffraction grating because
A.	The ions in a crystal are well arranged.
B.	The lines in a diffraction grating cannot reflect X-rays.
C.	The penetration power of X-rays is high in a diffraction grating.
D.	The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal
Answer» E.

Discussion

17.	X-rays are similar in nature to
A.	Cathode rays
B.	Positive rays
C.	?-rays
D.	?-rays
Answer» D. ?-rays

Discussion

18.	Radiation produced from TV picture tube is
A.	?-rays
B.	X-rays
C.	Far infrared.
D.	Infrared
Answer» C. Far infrared.

Discussion

19.	Ratio of the weight of H-atom to that of an electron is approximately
A.	18.336
B.	1836
C.	18360
D.	183.6
Answer» C. 18360

Discussion

20.	Radiation with wavelength longer than red lights
A.	Ultraviolet rays
B.	X-rays
C.	Infra red radiation
D.	Visible radiation
Answer» D. Visible radiation

Discussion

21.	The minimum wavelength of X-rays produced by the bombardment of electrons on the screen of a television set where the accelerating potential is 2.0K V will be
A.	6.2 x 10-10m
B.	9.1 x 10-18m
C.	3.11 x 10-10m
D.	4 x 10-10m
Answer» B. 9.1 x 10-18m

Discussion

22.	Reverse process of photoelectric effect is
A.	Pair production
B.	Compton effect
C.	Annihilation of matter
D.	X-rays production
Answer» E.

Discussion

23.	Reflecting mirrors in laser is used to
A.	Further stimulation
B.	Lasing more
C.	For producing more energetic lasers.
D.	All
Answer» B. Lasing more

Discussion

24.	The characteristic X-rays spectrum is due to
A.	The illumination of the target metal by ultra-violet radiation.
B.	The bombardment of the target by protons.
C.	The bombardment of target by electrons.
D.	The absorption of ? radiation by the target metal.
Answer» D. The absorption of ? radiation by the target metal.

Discussion

25.	The penetrating power of X-rays depends on their
A.	Applied voltage
B.	Frequency
C.	Source
D.	All of the above
Answer» C. Source

Discussion

26.	The radiations emitted form hydrogen filled discharge tube show
A.	Band spectrum
B.	Line spectrum
C.	Continuous spectrum
D.	Absorption spectrum
Answer» C. Continuous spectrum

Discussion

27.	The electric P.E of an electron in an orbit at a distance rn from the positive charge
A.	Ke2/rn
B.	Ke2/rn2
C.	?Ke2/rn
D.	?Ke2/rn2
Answer» D. ?Ke2/rn2

Discussion

28.	The minimum wavelength of X-rays can further be reduced by
A.	Reducing the pressure or cooling the target.
B.	Increasing the temperature of the filament.
C.	Using a target element of higher atomic number.
D.	Increasing the potential difference between the cathode and the target.
Answer» E.

Discussion

29.	The metastable state for an atom in laser light is
A.	10-4 sec
B.	10-5 sec
C.	10-3 sec
D.	10-8 sec
Answer» D. 10-8 sec

Discussion

30.	The penetrating power of X-rays is comparable with that of
A.	? - rays
B.	? - rays
C.	? - rays
D.	All of above
Answer» D. All of above

Discussion

31.	The velocity of laser light is
A.	Less than ordinary light.
B.	More than ordinary light.
C.	Equal to ordinary light.
D.	Different for different colours or frequency.
Answer» D. Different for different colours or frequency.

Discussion

32.	In He-Ne laser the lasing action is produced by
A.	Ne only.
B.	He-Ne both
C.	Electrons of He.
D.	Electrons Ne.
Answer» B. He-Ne both

Discussion

33.	In hydrogen spectrum which one of the following series lies in the ultraviolet region?
A.	Balmer series
B.	Pfund series
C.	Bracket series
D.	Lymann series
Answer» E.

Discussion

34.	In laser production the state in which more atoms are in the upper state than in the lower one is called
A.	Metal stable state.
B.	Normal state.
C.	Inverted population.
D.	All the above.
Answer» D. All the above.

Discussion

35.	In normal state of energy the incident high energy photons will be
A.	Stimulated.
B.	Absorbed.
C.	Cause X-ray emission.
D.	Cause laser production.
Answer» C. Cause X-ray emission.

Discussion

36.	Maximum frequency in the spectrum from X-ray tube is directly proportional to the
A.	Number of incident electron i.e. filament current.
B.	The kinetic energy of the incident electron i.e. the potential difference through which they are accelerated.
C.	The soft target which can easily emit electrons.
D.	All of above are correct.
Answer» C. The soft target which can easily emit electrons.

Discussion

37.	In obtaining an X-ray photograph of our hand we use the principle of
A.	Photo electric effect
B.	Ionization
C.	Shadow photograph
D.	Any of above
Answer» D. Any of above

Discussion

38.	Photon of highest frequency will be absorbed when transition takes place from
A.	1st to 5th orbit
B.	2nd to 5th orbit
C.	3rd to 5th orbit
D.	4th to 5th orbit
Answer» B. 2nd to 5th orbit

Discussion

39.	Quality of X-rays depends upon ___________ A-filament current B-accelerating voltage C-material of the target
A.	A&B
B.	B&C
C.	A&C
D.	A B & C
Answer» C. A&C

Discussion

Explore topic-wise MCQs in Physics.

Bracket series is obtained when all transition of electron terminate on

Electron cannot exist in the nucleus it is confirmed by observing that

In an electronic transition atom cannot emit

Excited atoms return to their ground state in

Hydrogen atom does not emit X-rays because

Ground state energy of the 4th orbit in a H-atom is

In an X-ray tube electrons each of charge e are accelerated through V potential difference allowed to hit a metal target. The wavelength of the X-rays emitted is

Total number of series in hydrogen spectrum is

UV radiation can be produced by

Wave-like characteristic of electron is demonstrated by

What is the velocity of a particle of mass m & de-Broglie wavelength ??

When we excite some atoms by heat collision or electrical discharge they will

When X-rays are passed through successive aluminum sheets what happens to their thickness?

Which one of following postulate is in accordance with the Rutherfords model?

X-ray are

X-rays are diffracted by a crystal but not by a diffraction grating because

X-rays are similar in nature to

Radiation produced from TV picture tube is

Ratio of the weight of H-atom to that of an electron is approximately

Radiation with wavelength longer than red lights

The minimum wavelength of X-rays produced by the bombardment of electrons on the screen of a television set where the accelerating potential is 2.0K V will be

Reverse process of photoelectric effect is

Reflecting mirrors in laser is used to

The characteristic X-rays spectrum is due to

The penetrating power of X-rays depends on their

The radiations emitted form hydrogen filled discharge tube show

The electric P.E of an electron in an orbit at a distance rn from the positive charge

The minimum wavelength of X-rays can further be reduced by

The metastable state for an atom in laser light is

The penetrating power of X-rays is comparable with that of

The velocity of laser light is

In He-Ne laser the lasing action is produced by

In hydrogen spectrum which one of the following series lies in the ultraviolet region?

In laser production the state in which more atoms are in the upper state than in the lower one is called

In normal state of energy the incident high energy photons will be

Maximum frequency in the spectrum from X-ray tube is directly proportional to the

In obtaining an X-ray photograph of our hand we use the principle of

Photon of highest frequency will be absorbed when transition takes place from

Quality of X-rays depends upon ___________ A-filament current B-accelerating voltage C-material of the target