JEE Main & Advanced Physics Atomic Physics Question Bank

Atomic Structure Total Questions - 174

1)

If in nature there may not be an element for which the principal quantum number n > 4, then the total possible number of elements will be [IIT 1983; MP PET 1999; RPMT 1999; RPET 2001]

A)
           60

B)
           32

C)
           4

D)
           64
View Solution
2)

In the Bohr's hydrogen atom model, the radius of the stationary orbit is directly proportional to (n = principle quantum number) [MNR 1988; SCRA 1994; CBSE PMT 1996; AIIMS 1999; DCE 2002]

A)
           \[\beta \]

B)
           n

C)
           \[{{n}^{-2}}\]

D)
           \[{{n}^{2}}\]
View Solution
3)

In the nth orbit, the energy of an electron \[{{E}_{n}}=-\frac{13.6}{{{n}^{2}}}eV\]for hydrogen atom. The energy required to take the electron from first orbit to second orbit will be [MP PMT 1987; CPMT 1991, 97; RPMT 1999; DCE 2001; Kerala PMT 2004]

A)
           \[10.2\ eV\]

B)
           \[12.1\ eV\]

C)
           \[13.6\ eV\]

D)
           \[3.4\ eV\]
View Solution
4)

In the following atoms and moleculates for the transition from n= 2 to n = 1, the spectral line of minimum wavelength will be produced by                                      [IIT 1983]

A)
           Hydrogen atom

B)
           Deuterium atom

C)
           Uni-ionized helium

D)
           di-ionized lithium
View Solution
5)

The Lyman series of hydrogen spectrum lies in the region [MNR 1993; MP PMT 1995; UPSEAT 2002]

A)
           Infrared

B)
           Visible

C)
           Ultraviolet

D)
           Of \[X-\] rays
View Solution
6)

The size of an atom is of the order of [CPMT 1990; MP PMT 1984; KCET 1994]

A)
           \[{{10}^{-8}}m\]

B)
           \[{{10}^{-10}}m\]

C)
           \[{{10}^{-12}}m\]

D)
           \[{{10}^{-14}}m\]
View Solution
7)

Which one of the series of hydrogen spectrum is in the visible region     [RPMT 1999;MP PET 1990; MP PMT 1994; AFMC 1998; CBSE PMT 1990; MH CET 2004]

A)
           Lyman series

B)
           Balmer series

C)
           Paschen series

D)
           Bracket series
View Solution
8)

The energy levels of the hydrogen spectrum is shown in figure. There are some transitions A, B, C, D and E. Transition A, B and C respectively represent [CPMT 1986, 88]

A)
           First member of Lyman series, third spectral line of Balmer series and the second spectral line of Paschen series

B)
           Ionization potential of hydrogen, second spectral line of Balmer series and third spectral line of Paschen series

C)
           Series limit of Lyman series, third spectral line of Balmer series and second spectral line of Paschen series

D)
           Series limit of Lyman series, second spectral line of Balmer series and third spectral line of Paschen series
View Solution
9)

In the above figure D and E respectively represent [CPMT 1986, 88]

A)
           Absorption line of Balmer series and the ionization potential of hydrogen

B)
           Absorption line of Balmer series and the wavelength lesser than lowest of the Lyman series

C)
           Spectral line of Balmer series and the maximum wavelength of Lyman series

D)
           Spectral line of Lyman series and the absorption of greater wavelength of limiting value of Paschen series
View Solution
10)

The Rutherford a-particle experiment shows that most of the a-particles pass through almost unscattered while some are scattered through large angles. What information does it give about the structure of the atom [AFMC 1997]

A)
           Atom is hollow

B)
           The whole mass of the atom is concentrated in a small centre called nucleus

C)
           Nucleus is positively charged

D)
           All the above
View Solution
11)

Which of the following is true                               [MP PET 1993]

A)
           Lyman series is a continuous spectrum

B)
           Paschen series is a line spectrum in the infrared

C)
           Balmer series is a line spectrum in the ultraviolet

D)
           The spectral series formula can be derived from the Rutherford model of the hydrogen atom
View Solution
12)

The energy required to knock out the electron in the third orbit of a hydrogen atom is equal to [DPMT 1987]

A)
           \[13.6\ eV\]

B)
           \[+\frac{13.6}{9}eV\]

C)
           \[-\frac{13.6}{3}eV\]

D)
           \[-\frac{3}{13.6}eV\]
View Solution
13)

An electron has a mass of \[9.1\times {{10}^{-31}}kg\]. It revolves round the nucleus in a circular orbit of radius \[0.529\times {{10}^{-10}}metre\]at a speed of \[2.2\times {{10}^{6}}m/s\]. The magnitude of its linear momentum in this motion is [AFMC 1988]

A)
           \[1.1\times {{10}^{-34}}kg-m/s\]

B)
           \[2.0\times {{10}^{-24}}kg-m/s\]

C)
           \[4.0\times {{10}^{-24}}kg-m/s\]

D)
           \[4.0\times {{10}^{-31}}kg-m/s\]
View Solution
14)

In a beryllium atom, if a0 be the radius of the first orbit, then the radius of the second orbit will be in general [CBSE PMT 1992; Roorkee 1993; BHU 1998]

A)
           \[n{{a}_{0}}\]

B)
           \[{{a}_{0}}\]

C)
           \[{{n}^{2}}{{a}_{0}}\]

D)
           \[\frac{{{a}_{0}}}{{{n}^{2}}}\]
View Solution
15)

The ionization potential for second He electron is

A)
           13.6 eV

B)
           27.2 eV

C)
           54.4 eV

D)
           100 eV
View Solution
16)

The energy required to remove an electron in a hydrogen atom from \[n=10\]state is [MP PMT 1993]

A)
           13.6 eV

B)
           1.36 eV

C)
           0.136 eV

D)
           0.0136 eV
View Solution
17)

Every series of hydrogen spectrum has an upper and lower limit in wavelength. The spectral series which has an upper limit of wavelength equal to 18752 Å is            [MP PMT 1993]

A)
           Balmer series

B)
           Lyman series

C)
           Paschen series

D)
           Pfund series (Rydberg constant \[R=1.097\times {{10}^{7}}\]per metre)
View Solution
18)

The kinetic energy of the electron in an orbit of radius r in hydrogen atom is (e = electronic charge [MP PMT 1987]

A)
           \[\frac{{{e}^{2}}}{{{r}^{2}}}\]

B)
           \[\frac{{{e}^{2}}}{2r}\]

C)
           \[\frac{{{e}^{2}}}{r}\]

D)
           \[\frac{{{e}^{2}}}{2{{r}^{2}}}\]
View Solution
19)

Ionization potential of hydrogen atom is 13.6 V. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. The spectral lines emitted by hydrogen atoms according to Bohr's theory will be                   [CPMT 1990; CBSE PMT 1996; MP PMT 1999; AMU (Med.) 2002]

A)
           One

B)
           Two

C)
           Three

D)
           Four
View Solution
20)

Energy levels A, B, C of a certain atom corresponding to increasing values of energy i.e. \[{{E}_{A}}<{{E}_{B}}<{{E}_{C}}\]. If \[{{\lambda }_{1}},\ {{\lambda }_{2}},\ {{\lambda }_{3}}\]are the wavelengths of radiations corresponding to the transitions C to B, B to A and C to A respectively, which of the following statements is correct            [AIIMS 1995; CBSE PMT 1990, 2005]

A)
           \[{{\lambda }_{3}}={{\lambda }_{1}}+{{\lambda }_{2}}\]

B)
           \[{{\lambda }_{3}}=\frac{{{\lambda }_{1}}{{\lambda }_{2}}}{{{\lambda }_{1}}+{{\lambda }_{2}}}\]

C)
           \[{{\lambda }_{1}}+{{\lambda }_{2}}+{{\lambda }_{3}}=0\]

D)
           \[\lambda _{3}^{2}=\lambda _{1}^{2}+\lambda _{2}^{2}\]
View Solution
21)

The angular momentum of electron in nth orbit is given by [Roorkee 1993]

A)
           nh

B)
           \[\frac{h}{2\pi n}\]

C)
           \[n\frac{h}{2\pi }\]

D)
           \[{{n}^{2}}\frac{h}{2\pi }\]
View Solution
22)

The ratio of the energies of the hydrogen atom in its first to second excited state is [CPMT 1978]

A)
           1/ 4

B)
           4/9

C)
           9/ 4

D)
           4
View Solution
23)

An electron jumps from the 4th orbit to the 2nd orbit of hydrogen atom. Given the Rydberg's constant \[R={{10}^{5}}c{{m}^{-1}}\]. The frequency in Hz of the emitted radiation will be                                               [CPMT 1976]

A)
           \[\frac{3}{16}\times {{10}^{5}}\]

B)
           \[\frac{3}{16}\times {{10}^{15}}\]

C)
           \[\frac{9}{16}\times {{10}^{15}}\]

D)
           \[\frac{3}{4}\times {{10}^{15}}\]
View Solution
24)

The ionisation potential of hydrogen atom is 13.6 volt. The energy required to remove an electron in the n = 2 state of the hydrogen atom is                           [NCERT 1983; MP PET 2005]

A)
           27.2 eV

B)
           13.6eV

C)
           6.8eV

D)
           3.4eV
View Solution
25)

The ionisation energy of 10 times ionised sodium atom is [DPMT 1991]

A)
           13.6 eV

B)
           \[13.6\times 11\ eV\]

C)
           \[\frac{13.6}{11}eV\]

D)
           \[13.6\times {{(11)}^{2}}eV\]
View Solution
26)

If the wavelength of the first line of the Balmer series of hydrogen is\[6561\ {AA}\], the wavelength of the second line of the series should be                                [CPMT 1984; DPMT 2004]

A)
\[13122\ {AA}\]

B)
\[3280\ {AA}\]

C)
\[4860\ {AA}\]

D)
\[2187\ {AA}\]
View Solution
27)

The following diagram indicates the energy levels of a certain atom when the system moves from 2E level to E, a photon of wavelength \[\lambda \] is emitted. The wavelength of photon produced during its transition from \[\frac{4E}{3}\] level to E is [CPMT 1989]

A)
           \[\lambda /3\]

B)
           \[3\lambda /4\]

C)
           \[4\lambda /3\]

D)
           \[3\lambda \]
View Solution
28)

A beam of fast moving alpha particles were directed towards a thin film of gold. The parts \[{A}',\ {B}'\]and \[{C}'\]of the transmitted and reflected beams corresponding to the incident parts A, B and C of the beam, are shown in the adjoining diagram. The number of alpha particles in [CPMT 1986, 88; RPET 2000]

A)
           \[{B}'\]will be minimum and in \[{C}'\]maximum

B)
           \[{A}'\]will be maximum and in \[{B}'\]minimum

C)
           \[{A}'\]will be minimum and in \[{B}'\]maximum

D)
           \[{C}'\]will be minimum and in \[{B}'\]maximum
View Solution
29)

According to Bohr's theory the radius of electron in an orbit described by principal quantum number n and atomic number Z is proportional to                                                           [CPMT 1988]

A)
           \[{{Z}^{2}}{{n}^{2}}\]

B)
           \[\frac{{{Z}^{2}}}{{{n}^{2}}}\]

C)
           \[\frac{{{Z}^{2}}}{n}\]

D)
           \[\frac{{{n}^{2}}}{Z}\]
View Solution
30)

The radius of electron's second stationary orbit in Bohr's atom is R. The radius of the third orbit will be [EAMCET 1992; DPMT 1999]

A)
           3 R

B)
           2.25 R

C)
           9 R

D)
           \[\frac{R}{3}\]
View Solution
31)

If m is mass of electron, v its velocity, r the radius of stationary circular orbit around a nucleus with charge Ze, then from Bohr's first postulate, the kinetic energy \[K=\frac{1}{2}m{{v}^{2}}\]of the electron in C.G.S. system is equal to [NCERT 1977]

A)
\[\frac{1}{2}\frac{Z{{e}^{2}}}{r}\]

B)
\[\frac{1}{2}\frac{Z{{e}^{2}}}{{{r}^{2}}}\]

C)
\[\frac{Z{{e}^{2}}}{r}\]

D)
\[\frac{Ze}{{{r}^{2}}}\]
View Solution
32)

Consider an electron in the nth orbit of a hydrogen atom in the Bohr model. The circumference of the orbit can be expressed in terms of the de Broglie wavelength \[\lambda \]of that electron as              [CBSE PMT 1990]

A)
           \[(0.259)\ n\lambda \]

B)
           \[\sqrt{n}\lambda \]

C)
           \[(13.6)\ \lambda \]

D)
           \[n\lambda \]
View Solution
33)

In any Bohr orbit of the hydrogen atom, the ratio of kinetic energy to potential energy of the electron is [MP PET 1994]

A)
           1/2

B)
           2

C)
           \[-1/2\]

D)
           ? 2
View Solution
34)

The spectral series of the hydrogen spectrum that lies in the ultraviolet region is the [CPMT 1990; MP PET 1994; MP PMT 2000]

A)
           Balmer series

B)
           Pfund series

C)
           Paschen series

D)
           Lyman series
View Solution
35)

Figure shows the energy levels P, Q, R, S and G of an atom where G is the ground state. A red line in the emission spectrum of the atom can be obtained by an energy level change from Q to S. A blue line can be obtained by following energy level change                                                [MP PMT 1994]

A)
           P to Q

B)
           Q to R

C)
           R to S

D)
           R to G
View Solution
36)

A hydrogen atom (ionisation potential 13.6 eV) makes a transition from third excited state to first excited state. The energy of the photon emitted in the process is                [MNR 1995]

A)
           1.89 eV

B)
           2.55 eV

C)
           12.09 eV

D)
           12.75 Ev
View Solution
37)

The figure indicates the energy level diagram of an atom and the origin of six spectral lines in emission (e.g. line no. 5 arises from the transition from level B to A). The following spectral lines will also occur in the absorption spectrum [CBSE PMT 1995]

A)
           1, 4, 6

B)
           4, 5, 6

C)
           1, 2, 3

D)
           1, 2, 3, 4, 5, 6
View Solution
38)

When a hydrogen atom is raised from the ground state to an excited state [CBSE PMT 1995; AMU (Med.) 1999]

A)
           P.E. increases and K.E. decreases

B)
           P.E. decreases and K.E. increases

C)
           Both kinetic energy and potential energy increase

D)
           Both K.E. and P.E. decrease
View Solution
39)

An electron makes a transition from orbit n = 4 to the orbit n = 2 of a hydrogen atom. The wave number of the emitted radiations (R = Rydberg's constant) will be [CBSE PMT 1995]

A)
           \[\frac{16}{3R}\]

B)
           \[\frac{2R}{16}\]

C)
           \[\frac{3R}{16}\]

D)
           \[\frac{4R}{16}\]
View Solution
40)

In Bohr model of the hydrogen atom, the lowest orbit corresponds to                   [Manipal MEE 1995]

A)
           Infinite energy

B)
           The maximum energy

C)
           The minimum energy

D)
           Zero energy
View Solution
41)

The ratio of the kinetic energy to the total energy of an electron in a Bohr orbit is [Roorkee 1995; BHU 2002]

A)
           ? 1

B)
           2

C)
           1 : 2

D)
           None of these
View Solution
42)

An electron in the n = 1 orbit of hydrogen atom is bound by 13.6 eV. If a hydrogen atom is in the n = 3 state, how much energy is required to ionize it                              [MP PMT 1995]

A)
           13.6 eV

B)
           4.53 eV

C)
           3.4 eV

D)
           1.51 eV
View Solution
43)

Which of the following statements about the Bohr model of the hydrogen atom is false [MP PMT 1995]

A)
           Acceleration of electron in n = 2 orbit is less than that in n = 1 orbit

B)
           Angular momentum of electron in n = 2 orbit is more than that in n = 1 orbit

C)
           Kinetic energy of electron in n = 2 orbit is less than that in n = 1 orbit

D)
           Potential energy of electron in n = 2 orbit is less than that in n = 1 orbit
View Solution
44)

If an electron jumps from 1st orbital to 3rd orbital, then it will                     [AFMC 1996]

A)
           Absorb energy

B)
           Release energy

C)
           No gain of energy

D)
           None of these
View Solution
45)

The ratio of the frequencies of the long wavelength limits of Lyman and Balmer series of hydrogen spectrum is [KCEE 1996]

A)
           27 : 5

B)
           5 : 27

C)
           4 : 1

D)
           1 : 4
View Solution
46)

Which of the following transitions in a hydrogen atom emits photon of the highest frequency [MP PET 1996; DPMT 2001]

A)
           n = 1 to n = 2

B)
           n = 2 to n = 1

C)
           n = 2 to n = 6

D)
           n = 6 to n = 2
View Solution
47)

In terms of Rydberg's constant R, the wave number of the first Balmer line is      [MP PMT 1996]

A)
           R

B)
           3R

C)
           \[\frac{5R}{36}\]

D)
           \[\frac{8R}{9}\]
View Solution
48)

If the ionisation potential of helium atom is 24.6 volt, the energy required to ionise it will be [MP PMT 1996]

A)
           24.6 eV

B)
           24.6 V

C)
           13.6 V

D)
           13.6 eV
View Solution
49)

Which of the transitions in hydrogen atom emits a photon of lowest frequency                 (n = quantum number) [BHU 1999]

A)
           n = 2 to n = 1

B)
           n = 4 to n = 3

C)
           n = 3 to n = 1

D)
           n = 4 to n = 2
View Solution
50)

According to Bohr's theory, the expressions for the kinetic and potential energy of an electron revolving in an orbit is given respectively by

A)
           \[+\frac{{{e}^{2}}}{8\pi {{\varepsilon }_{0}}r}\]and \[-\frac{{{e}^{2}}}{4\pi {{\varepsilon }_{0}}r}\]

B)
           \[+\frac{8\pi {{\varepsilon }_{0}}{{e}^{2}}}{r}\]and\[-\frac{4\pi {{\varepsilon }_{0}}{{e}^{2}}}{r}\]

C)
           \[-\frac{{{e}^{2}}}{8\pi {{\varepsilon }_{0}}r}\]and \[-\frac{{{e}^{2}}}{4\pi {{\varepsilon }_{0}}r}\]

D)
\[+\frac{{{e}^{2}}}{8\pi {{\varepsilon }_{0}}r}\]and \[+\frac{{{e}^{2}}}{4\pi {{\varepsilon }_{0}}r}\]
View Solution
51)

In a hydrogen atom, which of the following electronic transitions would involve the maximum energy change [MP PET 1997]

A)
           From n = 2 to n = 1

B)
           From n = 3 to n = 1

C)
           From n = 4 to n = 2

D)
           From n = 3 to n = 2
View Solution
52)

In the lowest energy level of hydrogen atom, the electron has the angular momentum [MP PET 1997; BCECE 2003]

A)
           \[\pi /h\]

B)
           \[h/\pi \]

C)
           \[h/2\pi \]

D)
           \[2\pi /h\]
View Solution
53)

The minimum energy required to excite a hydrogen atom from its ground state is [EAMCET (Engg.) 1995; MP PMT 1997; CPMT 1999; DCE 1999]

A)
           13.6 eV

B)
           \[-13.6\ eV\]

C)
           3.4eV

D)
           10.2 eV
View Solution
54)

Ratio of the wavelengths of first line of Lyman series and first line of Balmer series is [EAMCET (Engg.) 1995; MP PMT 1997]

A)
           1: 3

B)
           27 : 5

C)
           5 : 27

D)
           4 : 9
View Solution
55)

The Rydberg constant R for hydrogen is [MP PMT/PET 1998]

A)
\[R=-\left( \frac{1}{4\pi {{\varepsilon }_{0}}} \right).\frac{2{{\pi }^{2}}m{{e}^{2}}}{c{{h}^{2}}}\]

B)
\[R=\left( \frac{1}{4\pi {{\varepsilon }_{0}}} \right).\frac{2{{\pi }^{2}}m{{e}^{4}}}{c{{h}^{2}}}\]

C)
\[R={{\left( \frac{1}{4\pi {{\varepsilon }_{0}}} \right)}^{2}}.\frac{2{{\pi }^{2}}m{{e}^{4}}}{{{c}^{2}}{{h}^{2}}}\]

D)
\[R={{\left( \frac{1}{4\pi {{\varepsilon }_{0}}} \right)}^{2}}.\frac{2{{\pi }^{2}}m{{e}^{4}}}{c{{h}^{3}}}\]
View Solution
56)

The wavelength of the first line of Balmer series is \[6563\ {AA}\]. The Rydberg constant for hydrogen is about [MP PMT/PET 1998]

A)
\[1.09\times {{10}^{7}}per\ m\]

B)
\[1.09\times {{10}^{8}}per\ m\]

C)
\[1.09\times {{10}^{9}}per\ m\]

D)
\[1.09\times {{10}^{5}}per\ m\]
View Solution
57)

According to Bohr's theory the moment of momentum of an electron revolving in second orbit of hydrogen atom will be [MP PET 1999; KCET 2003]

A)
           \[2\pi h\]

B)
           \[\pi h\]

C)
           \[\frac{h}{\pi }\]

D)
           \[\frac{2h}{\pi }\]
View Solution
58)

The velocity of an electron in the second orbit of sodium atom (atomic number = 11) is v. The velocity of an electron in its fifth orbit will be                                                         [MP PET 1999]

A)
           v

B)
           \[\frac{22}{5}v\]

C)
           \[\frac{5}{2}v\]

D)
           \[\frac{2}{5}v\]
View Solution
59)

The absorption transitions between the first and the fourth energy states of hydrogen atom are 3. The emission transitions between these states will be    [MP PET 1999]

A)
           3

B)
           4

C)
           5

D)
           6
View Solution
60)

The ratio of longest wavelength and the shortest wavelength observed in the five spectral series of emission spectrum of hydrogen is                                                                   [MP PET 1999]

A)
           \[\frac{4}{3}\]

B)
           \[\frac{525}{376}\]

C)
           25

D)
           \[\frac{900}{11}\]
View Solution
61)

In the Bohr model of a hydrogen atom, the centripetal force is furnished by the coulomb attraction between the proton and the electron. If \[{{a}_{0}}\]is the radius of the ground state orbit, m is the mass, e is the charge on the electron and \[{{\varepsilon }_{0}}\]is the vacuum permittivity, the speed of the electron is [CBSE PMT 1998]

A)
           0

B)
           \[_{7}{{N}^{14}}\]

C)
           \[\frac{1}{4}\]

D)
           \[\frac{\sqrt{4\pi {{\varepsilon }_{0}}{{a}_{0}}m}}{e}\]
View Solution
62)

The electron in a hydrogen atom makes a transition\[{{n}_{1}}\to {{n}_{2}}\], where \[{{n}_{1}}\] and \[{{n}_{2}}\] are the principal quantum numbers of the two states. Assume the Bohr model to be valid. The time period of the electron in the initial state is eight times that in the final state. The possible values of n1 and n2 are                                         [IIT 1998; KCET 2005]

A)
           \[{{n}_{1}}=4,\ {{n}_{2}}=2\]

B)
           \[{{n}_{1}}=8,\ {{n}_{2}}=2\]

C)
           \[{{n}_{1}}=8,\ {{n}_{2}}=1\]

D)
           \[{{n}_{1}}=6,\ {{n}_{2}}=3\]
View Solution
63)

As per Bohr model, the minimum energy (in eV) required to remove an electron from the ground state of doubly ionized Li atom (Z = 3) is                                 [IIT 1997 Re-Exam; MH CET 2000]

A)
           1.51

B)
           13.6

C)
           40.8

D)
           122.4
View Solution
64)

Which one of these is non-divisible                        [KCET 1994]

A)
           Nucleus

B)
           Photon

C)
           Proton

D)
           Atom
View Solution
65)

In Bohr's model of hydrogen atom, let PE represents potential energy and TE the total energy. In going to a higher level                                                                      [KCET 1994]

A)
           PE decreases, TE increases

B)
           PE increases, TE increases

C)
           PE decreases, TE decreases

D)
           PE increases, TE decreases
View Solution
66)

According to Bohr's model, the radius of the second orbit of helium atom is                                         [Bihar MEE 1995]

A)
           0.53 Å

B)
           1.06 Å

C)
           2.12 Å

D)
           0.265 Å
View Solution
67)

The fact that photons carry energy was established by [ISM Dhanbad 1994]

A)
           Doppler's effect

B)
           Compton's effect

C)
           Bohr's theory

D)
           Diffraction of light
View Solution
68)

An ionic atom equivalent to hydrogen atom has wavelength equal to 1/4 of the wavelengths of hydrogen lines. The ion will be                                                                 [RPET 1997]

A)
           \[H{{e}^{+}}\]

B)
           \[L{{i}^{++}}\]

C)
           \[N{{e}^{9+}}\]

D)
           \[N{{a}^{10+}}\]
View Solution
69)

The extreme wavelengths of Paschen series are [RPET 1997]

A)
           \[0.365\mu m\]and \[0.565\mu m\]

B)
           \[0.818\mu m\]and \[1.89\mu m\]

C)
           \[1.45\mu m\]and \[4.04\mu m\]

D)
           \[2.27\mu m\]and \[7.43\mu m\]
View Solution
70)

The third line of Balmer series of an ion equivalent to hydrogen atom has wavelength of 108.5 nm. The ground state energy of an electron of this ion will be       [RPET 1997]

A)
           3.4 eV

B)
           13.6 eV

C)
           54.4 eV

D)
           122.4 eV
View Solution
71)

An electron in the n = 1 orbit of hydrogen atom is bound by 13.6 eV energy is required to ionize it is [MP PMT 2003]

A)
           13.6 eV

B)
           6.53 eV

C)
           5.4 eV

D)
           1.51 eV
View Solution
72)

Ionization energy of hydrogen is 13.6 eV. If \[h=6.6\times {{10}^{-34}}J-\]sec, the value of R will be of the order of [RPMT 1997]

A)
           \[{{10}^{10}}{{m}^{-1}}\]

B)
           \[{{10}^{7}}{{m}^{-1}}\]

C)
           \[{{10}^{4}}{{m}^{-1}}\]

D)
           \[{{10}^{-7}}{{m}^{-1}}\]
View Solution
73)

To explain his theory, Bohr used [CBSE PMT1993; MP PET 2002]

A)
           Conservation of linear momentum

B)
           Conservation of angular momentum

C)
           Conservation of quantum frequency

D)
           Conservation of energy
View Solution
74)

The ionisation energy of hydrogen atom is 13.6 eV. Following Bohr's theory, the energy corresponding to a transition between the 3rd and the 4th orbit is [CBSE PMT 1992; DPMT 2000; RPMT 1999; AMU (Med.) 2001]

A)
           3.40 eV

B)
           1.51 eV

C)
           0.85 eV

D)
           0.66 eV
View Solution
75)

Hydrogen atoms are excited from ground state of the principal quantum number 4. Then the number of spectral lines observed will be                                                      [CBSE PMT 1993]

A)
           3

B)
           6

C)
           5

D)
           2
View Solution
76)

Hydrogen atom emits blue light when it changes from n = 4 energy level to the n = 2 level. Which colour of light would the atom emit when it changes from the n = 5 level to the n = 2 level                                              [KCET 1993]

A)
           Red

B)
           Yellow

C)
           Green

D)
           Violet
View Solution
77)

In Rutherford scattering experiment, what will be the correct angle for \[\alpha \] scattering for an impact parameter b = 0                    [CBSE PMT 1994; JIPMER 2000]

A)
           \[{{90}^{o}}\]

B)
           \[{{270}^{o}}\]

C)
           \[{{0}^{o}}\]

D)
           \[{{180}^{o}}\]
View Solution
78)

The radius of hydrogen atom in its ground state is \[5.3\times {{10}^{-11}}m\]. After collision with an electron it is found to have a radius of \[21.2\times {{10}^{-11}}m\]. What is the principal quantum number n of the final state of the atom [CBSE PMT 1994; CPMT 2001; MH CET 2000]

A)
           n = 4

B)
           n = 2

C)
           n = 16

D)
           n = 3
View Solution
79)

The splitting of line into groups under the effect of electric or magnetic field is called                      [AFMC 1995]

A)
           Zeeman's effect

B)
           Bohr's effect

C)
           Heisenberg's effect

D)
           Magnetic effect
View Solution
80)

The energy of a hydrogen atom in its ground state is \[-13.6\ eV\]. The energy of the level corresponding to the quantum number n = 2 (first excited state) in the hydrogen atom is                  [CBSE PMT 1996; CBSE PMT 1997, 2001; MP PET 2000; AFMC 2000, 01, 02; BCECE 2003]

A)
           ? 2.72 eV

B)
           ? 0.85 eV

C)
           ? 0.54 eV

D)
           ? 3.4 eV
View Solution
81)

The first line of Balmer series has wavelength 6563 Å. What will be the wavelength of the first member of Lyman series [RPMT 1996]

A)
           1215.4 Å

B)
           2500 Å

C)
           7500 Å

D)
           600 Å
View Solution
82)

The wavelength of Lyman series is                          [BHU 1997]

A)
           \[\frac{4}{3\times 10967}cm\]

B)
           \[\frac{3}{4\times 10967}cm\]

C)
           \[\frac{4\times 10967}{3}cm\]

D)
           \[\frac{3}{4}\times 10967\ cm\]
View Solution
83)

When hydrogen atom is in its first excited level, its radius is .... its ground state radius                     [CBSE PMT 1997]

A)
           Half

B)
           Same

C)
           Twice

D)
           Four times
View Solution
84)

Hydrogen atom excites energy level from fundamental state to n = 3. Number of spectrum lines according to Bohr, is [CPMT 1997]

A)
           4

B)
           3

C)
           1

D)
           2
View Solution
85)

Number of spectral lines in hydrogen atom is   [CPMT 1997]

A)
           3

B)
           6

C)
           15

D)
           Infinite
View Solution
86)

In Bohr's model, the atomic radius of the first orbit is \[{{r}_{0}}\], then the radius of the third orbit is [AIIMS 1997; CPMT 2001; KCET (Engg./Med.) 1999; Pb. PMT 2004]

A)
           \[\frac{{{r}_{0}}}{9}\]

B)
           \[{{r}_{0}}\]

C)
           \[9{{r}_{0}}\]

D)
           \[3{{r}_{0}}\]
View Solution
87)

The wavelength of the energy emitted when electron come from fourth orbit to second orbit in hydrogen is \[20.397\,cm\]. The wavelength of energy for the same transition in \[H{{e}^{+}}\]is [AIIMS 1997; JIPMER 2000]

A)
           \[5.099\ c{{m}^{-1}}\]

B)
           \[20.497\ c{{m}^{-1}}\]

C)
           \[40.994\ c{{m}^{-1}}\]

D)
           \[81.988\ c{{m}^{-1}}\]
View Solution
88)

Minimum excitation potential of Bohr's first orbit in hydrogen atom is [BHU 1998; JIPMER 2001, 02; Pb. PMT 2004]

A)
           13.6 V

B)
           3.4 V

C)
           10.2 V

D)
           3.6 V
View Solution
89)

Which of the following statements are true regarding Bohr's model of hydrogen atom (I)       Orbiting speed of electron decreases as it shifts to discrete orbits away from the nucleus (II)     Radii of allowed orbits of electron are proportional to the principal quantum number (III) Frequency with which electrons orbits around the nucleus in discrete orbits is inversely proportional to the principal quantum number (IV)    Binding force with which the electron is bound to the nucleus increases as it shifts to outer orbits            Select correct answer using the codes given below Codes :                                                         [SCRA 1998]

A)
           I and III

B)
           II and IV

C)
           I, II and III

D)
           II, III and IV
View Solution
90)

The wavelength of radiation emitted is \[{{\lambda }_{0}}\]when an electron jumps from the third to the second orbit of hydrogen atom. For the electron jump from the fourth to the second orbit of the hydrogen atom, the wavelength of radiation emitted will be                                                                               [SCRA 1998; MP PET 2001; MH CET 2003]

A)
           \[\frac{16}{25}{{\lambda }_{0}}\]

B)
           \[\frac{20}{27}{{\lambda }_{0}}\]

C)
           \[\frac{27}{20}{{\lambda }_{0}}\]

D)
           \[\frac{25}{16}{{\lambda }_{0}}\]
View Solution
91)

For electron moving in nth orbit of H-atom the angular velocity is proportional to                                                [RPET 1999]

A)
           n

B)
           1/n

C)
           n3

D)
           1/n3
View Solution
92)

The energy of electron in first excited state of H-atom is \[-\ 3.4\ eV\] its kinetic energy is [RPET 1999; CBSE PMT 2005]

A)
           ? 3.4 eV

B)
           + 3.4 eV

C)
           ? 6.8 eV

D)
           6.8 eV
View Solution
93)

The energy required to excite an electron from the ground state of hydrogen atom to the first excited state, is [Pb. PMT 1999]

A)
           \[1.602\times {{10}^{-14}}\,J\]

B)
           \[1.619\times {{10}^{-16}}\,J\]

C)
           \[1.632\times {{10}^{-18}}J\]

D)
           \[1.656\times {{10}^{-20}}J\]
View Solution
94)

Which of the following phenomena suggests the presence of electron energy levels in atoms    [JIPMER 1999]

A)
           Radioactive decay

B)
           Isotopes

C)
           Spectral lines

D)
           a-particles scattering
View Solution
95)

Which of the following spectral series in hydrogen atom give spectral line of 4860 Å                         [Roorkee 1999]

A)
           Lyman

B)
           Balmer

C)
           Paschen

D)
           Brackett
View Solution
96)

If scattering particles are 56 for \[{{90}^{o}}\] angle then this will be at \[{{60}^{o}}\] angle                                           [RPMT 2000]

A)
           224

B)
           256

C)
           98

D)
           108
View Solution
97)

When an electron in hydrogen atom is excited, from its 4th to 5th stationary orbit, the change in angular momentum of electron is (Planck?s constant: \[h=6.6\times {{10}^{-34}}J\text{-s}\]) [AFMC 2000; Pb. PET 2001]

A)
           \[4.16\times {{10}^{-34}}\,J\text{-}s\]

B)
           \[3.32\times {{10}^{-34}}\,J\text{-}s\]

C)
           \[1.05\times {{10}^{-34}}\,J\text{-}s\]

D)
           \[2.08\times {{10}^{-34}}\,J\text{-}s\]
View Solution
98)

Energy of electron in a orbit of H-atom is             [RPET 2000]

A)
           Positive

B)
           Negative

C)
           Zero

D)
           Nothing can be said
View Solution
99)

The concept of stationary orbits was proposed by [Pb. PMT 2000]

A)
           Neil Bohr

B)
           J.J. Thomson

C)
           Ruther ford

D)
           I. Newton
View Solution
100)

In a hydrogen atom, the distance between the electron and proton is \[2.5\times {{10}^{-11}}\,m\]. The electrical force of attraction between them will be                                                               [Pb. PMT 2000]

A)
           \[2.8\times {{10}^{-7}}\,N\]

B)
           \[3.7\times {{10}^{-7}}N\]

C)
           \[6.2\times {{10}^{-7}}N\]

D)
           \[9.1\times {{10}^{-7}}N\]
View Solution
101)

If \[{{\lambda }_{\text{max}}}\] is 6563 Å, then wave length of second line for Balmer series will be                                            [RPMT 2000]

A)
           \[\lambda =\frac{16}{3R}\]

B)
           \[\lambda =\frac{36}{5R}\]

C)
           \[\lambda =\frac{4}{3R}\]

D)
           None of the above
View Solution
102)

What will be the angular momentum of a electron, if energy of this electron in H-atom is 1.5eV (in J-sec) [RPMT 2000]

A)
           \[1.05\times {{10}^{-34}}\]

B)
           \[2.1\times {{10}^{-34}}\]

C)
           \[3.15\times {{10}^{-34}}\]

D)
           \[-2.1\times {{10}^{-34}}\]
View Solution
103)

Who discovered spin quantum number              [RPMT 2000]

A)
           Unlenbeck and Goudsmit

B)
           Nell?s Bohr

C)
           Zeeman

D)
           Sommerfield
View Solution
104)

The time of revolution of an electron around a nucleus of charge Ze in nth Bohr orbit is directly proportional to [MP PET 2003]

A)
           n

B)
           \[\frac{{{n}^{3}}}{{{Z}^{2}}}\]

C)
           \[\frac{{{n}^{2}}}{Z}\]

D)
           \[\frac{Z}{n}\]
View Solution
105)

In Bohr?s model, if the atomic radius of the first orbit is \[{{r}_{0}}\], then the radius of the fourth orbit is              [CBSE PMT 2000]

A)
           \[{{r}_{0}}\]

B)
           \[4{{r}_{0}}\]

C)
           \[{{r}_{0}}/16\]

D)
           \[16{{r}_{0}}\]
View Solution
106)

If R is the Rydberg?s constant for hydrogen the wave number of the first line in the Lyman series will be [KCET 2000]

A)
           \[\frac{R}{4}\]

B)
           \[\frac{3R}{4}\]

C)
           \[\frac{R}{2}\]

D)
           2R
View Solution
107)

In hydrogen atom, if the difference in the energy of the electron in \[n=2\] and \[n=3\] orbits is E, the ionization energy of hydrogen atom is                                   [EAMCET (Med.) 2000]

A)
           13.2 E

B)
           7.2 E

C)
           5.6 E

D)
           3.2 E
View Solution
108)

The first member of the Paschen series in hydrogen spectrum is of wavelength 18,800 Å. The short wavelengths limit of Paschen series is                                            [EAMCET (Med.) 2000]

A)
           1215 Å

B)
           6560 Å

C)
           8225 Å

D)
           12850 Å
View Solution
109)

The ratio of the largest to shortest wavelengths in Lyman series of hydrogen spectra is [EAMCET (Med.) 2000]

A)
           \[\frac{25}{9}\]

B)
           \[\frac{17}{6}\]

C)
           \[\frac{9}{5}\]

D)
           \[\frac{4}{3}\]
View Solution
110)

In Bohr model of hydrogen atom, the ratio of periods of revolution of an electron in \[n=2\] and \[n=1\] orbits is [EAMCET (Engg.) 2000]

A)
           2 : 1

B)
           4 : 1

C)
           8 : 1

D)
           16 : 1
View Solution
111)

The ratio of the longest to shortest wavelengths in Brackett series of hydrogen spectra is        [EAMCET (Engg.) 2000]

A)
           \[\frac{25}{9}\]

B)
           \[\frac{17}{6}\]

C)
           \[\frac{9}{5}\]

D)
           \[\frac{4}{3}\]
View Solution
112)

The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true                                      [IIT JEE (Screening) 2000]

A)
           Its kinetic energy increases and its potential and total energies decrease

B)
           Its kinetic energy decreases, potential energy increases and its total energy remains the same

C)
           Its kinetic and total energies decrease and its potential energy increases

D)
           Its kinetic, potential and total energies decreases
View Solution
113)

The ratio of minimum to maximum wavelength in Balmer series is                                            [MP PET 2000]

A)
           5 : 9

B)
           5 : 36

C)
           1 : 4

D)
           3 : 4
View Solution
114)

The radius of the Bohr orbit in the ground state of hydrogen atom is 0.5 Å. The radius of the orbit of the electron in the third excited state of \[H{{e}^{+}}\] will be                                          [MP PMT 2000]

A)
           8 Å

B)
           4 Å

C)
           0.5 Å

D)
           0.25 Å
View Solution
115)

The ratio of the speed of the electron in the first Bohr orbit of hydrogen and the speed of light is equal to (where e, h and c have their usual meanings)               [MP PMT 2000]

A)
           \[2\pi hc/{{e}^{2}}\]

B)
           \[{{e}^{2}}h/2\pi c\]

C)
           \[{{e}^{2}}c/2\pi h\]

D)
           \[2\pi {{e}^{2}}/hc\]
View Solution
116)

According to the Rutherford?s atomic model, the electrons inside the atom are                                                 [KCET (Med.) 2000]

A)
           Stationary

B)
           Not stationary

C)
           Centralized

D)
           None of these
View Solution
117)

The energy of hydrogen atom in its ground state is ? 13.6 eV. The energy of the level corresponding to the quantum number n is equal 5 is                              [KCET (Engg./Med.) 2001]

A)
           ? 5.40 eV

B)
           ? 2.72 eV

C)
           ? 0.85 eV

D)
           ? 0.54 eV
View Solution
118)

According to classical theory, the circular path of an electron in Rutherford atom is                                           [BHU 2001]

A)
           Spiral

B)
           Circular

C)
           Parabolic

D)
           Straight line
View Solution
119)

Rutherford?s a-particle experiment showed that the atoms have                                             [AFMC 2001]

A)
           Proton

B)
           Nucleus

C)
           Neutron

D)
           Electrons
View Solution
120)

Orbital acceleration of electron is                            [RPET 2001]

A)
           \[\frac{{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}{{m}^{2}}{{r}^{3}}}\]

B)
           \[\frac{{{n}^{2}}{{h}^{2}}}{2{{n}^{2}}{{r}^{3}}}\]

C)
           \[\frac{4{{n}^{2}}{{h}^{2}}}{{{\pi }^{2}}{{m}^{2}}{{r}^{3}}}\]

D)
           \[\frac{4{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}{{m}^{2}}{{r}^{3}}}\]
View Solution
121)

Which of the following is true for number of spectral lines in going form Layman series to Pfund series [RPET 2001]

A)
           Increases

B)
           Decreases

C)
           Unchanged

D)
           May decreases or increases
View Solution
122)

The wavelength of yellow line of sodium is 5896 Å. Its wave number will be                                         [MP PET 2001]

A)
           50883 × 1010 per second

B)
           16961 per cm

C)
           17581 per cm

D)
           50883 per cm
View Solution
123)

Radius of the first orbit of the electron in a hydrogen atom is 0.53 Å. So, the radius of the third orbit will be [Kerala (Engg.) 2001]

A)
           2.12 Å

B)
           4.77 Å

C)
           1.06 Å

D)
           1.59 Å
View Solution
124)

The first line in the Lyman series has wavelength l. The wavelength of the first line in Balmer series is [MH CET (Med.) 2001]

A)
           \[\frac{2}{9}\,\lambda \]

B)
           \[\frac{9}{2}\,\lambda \]

C)
           \[\frac{5}{27}\,\lambda \]

D)
           \[\frac{27}{5}\lambda \]
View Solution
125)

In hydrogen atom which quantity is integral multiple of \[\frac{h}{2\pi }\] [DCE 2001]

A)
           Angular momentum

B)
           Angular velocity

C)
           Angular acceleration

D)
           Momentum
View Solution
126)

In the following transitions, which one has higher frequency [UPSEAT 2001]

A)
           3 ? 2

B)
           4 ? 3

C)
           4 ? 2

D)
           3 ? 1
View Solution
127)

The diagram shows the path of four a-particles of the same energy being scattered by the nucleus of an atom simultaneously. Which of these are/is not physically possible [AMU (Med.) 2001]

A)
           3 and 4

B)
           2 and 3

C)
           1 and 4

D)
           4 only
View Solution
128)

An electron jumps from 5th orbit to 4th orbit of hydrogen atom. Taking the Rydberg constant as \[{{10}^{7}}\] per metre. What will be the frequency of radiation emitted [Pb. PMT 2001]

A)
           \[6.75\times {{10}^{12}}\,Hz\]

B)
           \[6.75\times {{10}^{14}}\,Hz\]

C)
           \[6.75\times {{10}^{13}}\,Hz\]

D)
           None of these
View Solution
129)

For principal quantum number \[n=3\], the possible values of orbital quantum number ?l? are [MP PET 2001; MP PMT 2001]

A)
           1, 2, 3

B)
           0, 1, 2, 3

C)
           0, 1, 2

D)
           ?1, 0, +1
View Solution
130)

Four lowest energy levels of H-atom are shown in the figure. The number of possible emission lines would be                                                                                                                                                                                                                         [MP PMT 2001]

A)
           3

B)
           4

C)
           5

D)
           6
View Solution
131)

The order of the size of nucleus and Bohr radius of an atom respectively are       [MP PET 2001; MP PMT 2001]

A)
           \[{{10}^{-14}}m,\ {{10}^{-10}}m\]

B)
           \[{{10}^{-10}}\,m,\,{{10}^{-8}}\,m\]

C)
           \[{{10}^{-20}}m,\ {{10}^{-16}}m\]

D)
           \[{{10}^{-8}}\,m,\,{{10}^{-6}}\,m\]
View Solution
132)

Energy of an electron in an excited hydrogen atom is ? 3.4 eV. Its angular momentum will be: \[h=6.626\times {{10}^{-34}}J-s\] [UPSEAT 1999; Kerala PET 2002]

A)
           \[1.11\times {{10}^{34}}J\ \sec \]

B)
           \[1.51\times {{10}^{-31}}J\ \sec \]

C)
           \[2.11\times {{10}^{-34}}J\ \sec \]

D)
           \[3.72\times {{10}^{-34}}J\ \sec \]
View Solution
133)

The ratio of the wavelengths for 2 ® 1 transition in Li++, He+ and H is                                       [UPSEAT 2003]

A)
           1 : 2 : 3

B)
           1 : 4 : 9

C)
           4 : 9 : 36

D)
           3 : 2 : 1
View Solution
134)

The wavelength of light emitted from second orbit to first orbits in a hydrogen atom is                  [Pb. PMT 2002]

A)
           \[1.215\times {{10}^{-7}}m\]

B)
           \[1.215\times {{10}^{-5}}m\]

C)
           \[1.215\times {{10}^{-4}}m\]

D)
           \[1.215\times {{10}^{-3}}m\]
View Solution
135)

Energy of the electron in nth orbit of hydrogen atom is given by \[{{E}_{n}}=-\frac{13.6}{{{n}^{2}}}eV\]. The amount of energy needed to transfer electron from first orbit to third orbit is [MH CET 2002; Kerala PMT 2002]

A)
           13.6 eV

B)
           3.4 eV

C)
           12.09 eV

D)
           1.51 eV
View Solution
136)

The ratio of speed of an electron in ground state in Bohrs first orbit of hydrogen atom to velocity of light in air is [MH CET 2002]

A)
           \[\frac{{{e}^{2}}}{2{{\varepsilon }_{0}}hc}\]

B)
           \[\frac{2{{e}^{2}}{{\varepsilon }_{0}}}{hc}\]

C)
           \[\frac{{{e}^{3}}}{2{{\varepsilon }_{0}}hc}\]

D)
           \[\frac{2{{\varepsilon }_{0}}hc}{{{e}^{2}}}\]
View Solution
137)

Whenever a hydrogen atom emits a photon in the Balmer series                                              [KCET 2002]

A)
           It need not emit any more photon

B)
           It may emit another photon in the Paschen series

C)
           It must emit another photon in the Lyman series

D)
           It may emit another photon in the Balmer series
View Solution
138)

The de-Broglie wavelength of an electron in the first Bohr orbit is                             [KCET 2002]

A)
           Equal to one fourth the circumference of the first orbit

B)
           Equal to half the circumference of the first orbit

C)
           Equal to twice the circumference of the first orbit

D)
           Equal to the circumference of the first orbit
View Solution
139)

In hydrogen atom, when electron jumps from second to first orbit, then energy emitted is                          [AIEEE 2002]

A)
           ? 13.6 eV

B)
           ? 27.2 eV

C)
           ? 6.8 eV

D)
           None of these
View Solution
140)

Minimum energy required to takeout the only one electron from ground state of \[H{{e}^{+}}\] is                           [CPMT 2002]

A)
           13.6 eV

B)
           54.4 eV

C)
           27.2 eV

D)
           6.8 eV
View Solution
141)

The frequency of 1st line of Balmer series in \[{{H}_{2}}\] atom is \[{{\nu }_{0}}\]. The frequency of line emitted by singly ionised He atom is [CPMT 2002]

A)
           \[2{{\nu }_{0}}\]

B)
           \[4{{\nu }_{0}}\]

C)
           \[{{\nu }_{0}}/2\]

D)
           \[{{\nu }_{0}}/4\]
View Solution
142)

When the electron in the hydrogen atom jumps from 2nd orbit to 1st orbit, the wavelength of radiation emitted is l. When the electrons jump from 3rd orbit to 1st orbit, the wavelength of emitted radiation would be       [MP PMT 2002]

A)
           \[\frac{27}{32}\lambda \]

B)
           \[\frac{32}{27}\lambda \]

C)
           \[\frac{2}{3}\lambda \]

D)
           \[\frac{3}{2}\lambda \]
View Solution
143)

The possible quantum number for 3d electron are [MP PMT 2002]

A)
           \[n=3,\,l=1,\,{{m}_{l}}=+1,\,{{m}_{s}}=-\frac{1}{2}\]

B)
           \[n=3,\,l=2,\,{{m}_{l}}=+2,\,{{m}_{s}}=-\frac{1}{2}\]

C)
           \[n=3,\,l=1,\,{{m}_{l}}=-1,\,{{m}_{s}}=+\frac{1}{2}\]

D)
           \[n=3,\,l=0,\,{{m}_{l}}=+1,\,{{m}_{s}}=-\frac{1}{2}\]
View Solution
144)

The radius of the first (lowest) orbit of the hydrogen atom is \[{{a}_{0}}.\] The radius of the second (next higher) orbit will be                                                                   [MP PET 2002; MP PMT 2004]

A)
           \[4{{a}_{0}}\]

B)
           \[6{{a}_{0}}\]

C)
           \[8{{a}_{0}}\]

D)
           \[10{{a}_{0}}\]
View Solution
145)

Which of the following transition will have highest emission wavelength                                               [BHU 2003]

A)
           \[n=2\text{ to} n=1\]

B)
           \[n=1\text{ to }n=2\]

C)
           \[n=2\text{ }\,\text{to}\,\,n=5\]

D)
           \[n=5\text{ to }n=2\]
View Solution
146)

When the wave of hydrogen atom comes from infinity into the first orbit then the value of wave number is        [RPET 2003]

A)
           109700 cm?1

B)
           1097cm?1

C)
           109 cm?1

D)
           None of these
View Solution
147)

With the increase in principle quantum number, the energy difference between the two successive energy levels [RPET 2003]

A)
           Increases

B)
           Decreases

C)
           Remains constant

D)
           Sometimes increases and sometimes decreases
View Solution
148)

In which of the following systems will the radius of the first orbit \[(n=1)\] be minimum [Kerala PET 2002; CBSE PMT 2003]

A)
           Single ionized helium

B)
           Deuterium atom

C)
           Hydrogen atom

D)
           Doubly ionized lithium
View Solution
149)

If the binding energy of the electron in a hydrogen atom is 13.6 eV, the energy required to remove the electron from the first excited state of \[L{{i}^{++}}\] is                                                      [AIEEE 2003]

A)
           122.4 eV

B)
           30.6 eV

C)
           13.6 eV

D)
           3.4 eV
View Solution
150)

Which of the following is quantised according to Bohr?s theory of hydrogen atom                                                                   [MP PMT 2004]

A)
           Linear momentum of electron

B)
           Angular momentum of electron

C)
           Linear velocity of electron

D)
           Angular velocity of electron
View Solution
151)

The shortest wavelength in the Lyman series of hydrogen spectrum is 912 Å corresponding to a photon energy of 13.6 eV. The shortest wavelength in the Balmer series is about                   [MP PMT 2004]

A)
           3648 Å

B)
           8208 Å

C)
           1228 Å

D)
           6566 Å
View Solution
152)

Energy E of a hydrogen atom with principal quantum number n is given by \[E=\frac{-13.6}{{{n}^{2}}}eV\]. The energy of a photon ejected when the electron jumps from \[n=3\] state to \[n=2\] state of hydrogen is approximately         [CBSE PMT 2004]

A)
           1.5 eV

B)
           0.85 eV

C)
           3.4 eV

D)
           1.9 eV
View Solution
153)

The Bohr model of atoms                                    [CBSE PMT 2004]

A)
           Assumes that the angular momentum of electrons is quantized

B)
           Uses Einstein?s photo-electric equation

C)
           Predicts continuous emission spectra for atoms

D)
           Predicts the same emission spectra for all types of atoms
View Solution
154)

The colour of the second line of Balmer series is [J & K CET 2004]

A)
           Blue

B)
           Yellow

C)
           Red

D)
           Violet
View Solution
155)

Which state of triply ionised Baryllium \[(B{{e}^{+++}})\] has the same orbital radius as that of the ground state of hydrogen [KCET 2004]

A)
           n = 4

B)
           n = 3

C)
           n = 2

D)
           n = 1
View Solution
156)

The ratio of areas within the electron orbits for the first excited state to the ground state for hydrogen atom is [BCECE 2004]

A)
           16 : 1

B)
           18 : 1

C)
           4 : 1

D)
           2 : 1
View Solution
157)

The kinetic energy of an electron revolving around a nucleus will be                                        [BCECE 2004]

A)
           Four times of P.E.

B)
           Double of P.E.

C)
           Equal to P.E.

D)
           Half of its P.E.
View Solution
158)

Taking Rydberg?s constant \[{{R}_{H}}=1.097\times {{10}^{7}}m\] first and second wavelength of Balmer series in hydrogen spectrum is [Pb. PMT 2004]

A)
           2000 Å, 3000 Å

B)
           1575 Å, 2960 Å

C)
           6529 Å, 4280 Å

D)
           6552 Å, 4863 Å
View Solution
159)

The kinetic energy of electron in the first Bohr orbit of the hydrogen atom is                                       [Pb. PET 2000]

A)
           ? 6.5 eV

B)
           ? 27.2 eV

C)
           13.6 eV

D)
           ? 13.6 eV
View Solution
160)

In the spectrum of hydrogen atom, the ratio of the longest wavelength in Lyman series to the longest wavelength in the Balmer series is                                                           [UPSEAT 2004]

A)
           5/27

B)
           1/93

C)
           4/9

D)
           3/2
View Solution
161)

In Bohr?s model of hydrogen atom, which of the following pairs of quantities are quantized                         [UPSEAT 2004]

A)
           Energy and linear momentum

B)
           Linear and angular momentum

C)
           Energy and angular momentum

D)
           None of the above
View Solution
162)

The energy of the highest energy photon of Balmer series of hydrogen spectrum is close to                        [UPSEAT 2004]

A)
           13.6 eV

B)
           3.4 eV

C)
           1.5 eV

D)
           0.85 eV
View Solution
163)

Energy of an electron in nth orbit of hydrogen atom is \[\left( k=\frac{1}{4\pi {{\varepsilon }_{0}}} \right)\]                                               [DCE 2002]

A)
           \[-\frac{2{{\pi }^{2}}{{k}^{2}}m{{e}^{4}}}{{{n}^{2}}{{h}^{2}}}\]

B)
           \[-\frac{4{{\pi }^{2}}\,m\,k{{e}^{2}}}{{{n}^{2}}{{h}^{2}}}\]

C)
           \[-\frac{{{n}^{2}}{{h}^{2}}}{2\pi \,k\,m{{e}^{4}}}\]

D)
           \[-\frac{{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}\,k\,m{{e}^{2}}}\]
View Solution
164)

Which one of the relation is correct between time period and number of orbits while an electron is revolving in a orbit [DPMT 2003]

A)
           \[{{n}^{2}}\]

B)
           \[\frac{1}{{{n}^{2}}}\]

C)
           \[{{n}^{3}}\]

D)
           \[\frac{1}{n}\]
View Solution
165)

An electron changes its position from orbit \[n=4\] to the orbit \[n=2\] of an atom. The wavelength of the emitted radiation?s is (R = Rydberg?s constant)                    [BHU 2004]

A)
           \[\frac{16}{R}\]

B)
           \[\frac{16}{3R}\]

C)
           \[\frac{16}{5R}\]

D)
           \[\frac{16}{7R}\]
View Solution
166)

If the energy of a hydrogen atom in nth orbit is \[{{E}_{n}}\], then energy in the nth orbit of a singley ionized helium atom will be                                                                                   [BHU 2004]

A)
           \[4{{E}_{n}}\]

B)
           \[{{E}_{n}}/4\]

C)
           \[2{{E}_{n}}\]

D)
           \[{{E}_{n}}/2\]
View Solution
167)

What is the ratio of wavelength of radiations emitted when an electron in hydrogen atom jump from fourth orbit to second orbit and from third orbit to second orbit [MH CET 2004]

A)
           27 : 25

B)
           20 : 27

C)
           20 : 25

D)
           25 : 27
View Solution
168)

The energy of electron in the nth orbit of hydrogen atom is expressed as \[{{E}_{n}}=\frac{-13.6}{{{n}^{2}}}eV\]. The shortest and longest wavelength of Lyman series will be [Pb. PET 2003]

A)
           910 Å, 1213 Å

B)
           5463 Å, 7858 Å

C)
           1315 Å, 1530 Å

D)
           None of these
View Solution
169)

The ground state energy of hydrogen atom is ? 13.6 eV. What is the potential energy of the electron in this state                                                                                              [AIIMS 2005]

A)
           0 eV

B)
           ? 27.2 eV

C)
           1 eV

D)
           2 eV
View Solution
170)

The diagram shows-the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy       [AIEEE 2005]

A)
           I

B)
           II

C)
           III

D)
           IV
View Solution
171)

As the electron in Bohr orbit of Hydrogen atom passes from state \[n=2\] to \[n=1\], the kinetic energy K and potential energy U change as                                                   [MP PET 2005]

A)
           K two-fold, U four-fold

B)
           K four-fold, U two-fold

C)
           K four-fold, U also four-fold

D)
           K two-fold, U also two-fold
View Solution
172)

The magnetic moment \[(\mu )\]of a revolving electron around the nucleus varies with principal quantum number n as [AIIMS 2005]

A)
           \[\mu \propto n\]

B)
           \[\mu \propto 1/n\]

C)
           \[\mu \propto {{n}^{2}}\]

D)
           \[\mu \propto 1/{{n}^{2}}\]
View Solution
173)

Bohr's atom model assumes                                      [KCET 2005]

A)
           The nucleus is of infinite mass and is at rest

B)
           Electrons in a quantized orbit will not radiate energy

C)
           Mass of electron remains constant

D)
           All the above conditions
View Solution
174)

Radius of first Bohr orbit is r. What is the radius of 2nd Bohr orbit?                                              [BHU 2005]

A)
           8r

B)
           2r

C)
           4r

D)
           \[2\sqrt{2r}\]
View Solution

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JEE Main & Advanced Physics Atomic Physics Question Bank

done Atomic Structure Total Questions - 174

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Atomic Structure Total Questions - 174