Atoms and Nuclei

190 questions · Physics · JEE Main

Atoms and Nuclei

190 questions · Physics · JEE Main

Considering Bohr's atomic model for hydrogen atom : (A) the energy of H atom in ground state is same as energy of $He^{+}$ ion in its first excited state. (B) the energy of H atom in ground state is same as that for $Li^{++}$ …2025 · 2 Apr · Shift 1 · Q63 · MCQ
Energy released when two deuterons $(_{1} H^{2})$ fuse to form a helium nucleus $(_{2} He^{4})$ is : (Given : Binding energy per nucleon of $_{1} H^{2} = 1.1 MeV$ and binding energy per…2025 · 2 Apr · Shift 2 · Q64 · MCQ
Assuming the validity of Bohr's atomic model for hydrogen like ions the radius of $Li^{++}$ ion in its ground state is given by $\frac{1}{X} a_{0}$ , where $X =$ (Where $a_{0}$ is the first Bohr's…2025 · 2 Apr · Shift 2 · Q70 · MCQ
$Match the LIST-I with LIST-II$ $Choose the correct answer from the options given below:$ Includes table2025 · 3 Apr · Shift 1 · Q63 · MCQ
Given below are two statements: one is labelled as $Assertion A$ and the other is labelled as Reason $R$ Assertion A : The Bohr model is applicable to hydrogen and hydrogen-like atoms only. Reason $R$ …2025 · 3 Apr · Shift 2 · Q68 · MCQ
An electron in the hydrogen atom initially in the fourth excited state makes a transition to $n^{th}$ energy state by emitting a photon of energy 2.86 eV . The integer value of n will be .2025 · 3 Apr · Shift 2 · Q71 · Numerical
Considering the Bohr model of hydrogen like atoms, the ratio of the radius of $5^{th}$ orbit of the electron in $Li^{2 +}$ and $He^{+}$ is2025 · 4 Apr · Shift 1 · Q60 · MCQ
A radioactive material $P$ first decays into $Q$ and then $Q$ decays to non-radioactive material $R$ . Which of the following figure represents time dependent mass of $P, Q$ and $R$ ?2025 · 4 Apr · Shift 2 · Q52 · MCQ
Given below are two statements : Statement (I) : The dimensions of Planck's constant and angular momentum are same. Statement (II) : In Bohr's model electron revolve around the nucleus only in those orbits for which angular momentum is…2025 · 4 Apr · Shift 2 · Q70 · MCQ
In a hydrogen like ion, the energy difference between the $2^{nd}$ excitation energy state and ground is 108.8 eV . The atomic number of the ion is:2025 · 7 Apr · Shift 1 · Q63 · MCQ
For a hydrogen atom, the ratio of the largest wavelength of Lyman series to that of the Balmer series is2025 · 7 Apr · Shift 1 · Q67 · MCQ
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The density of the copper $(_{29}^{64} Cu)$ nucleus is greater than that of the carbon $(_{6}^{12} C)$ …2025 · 7 Apr · Shift 2 · Q63 · MCQ
For a nucleus of mass number A and radius R, the mass density of nucleus can be represented as2025 · 8 Apr · Shift 2 · Q55 · MCQ
A radioactive nucleus $n_{2}$ has 3 times the decay constant as compared to the decay constant of another radioactive nucleus $n_{1}$ . If initial number of both nuclei are the same, what is the ratio of number of nuclei of $n_{2}$ to…2025 · 23 Jan · Shift 1 · Q59 · MCQ
Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The binding energy per nucleon is found to be practically independent of the atomic number A , for nuclei with mass…2025 · 23 Jan · Shift 2 · Q57 · MCQ
During the transition of electron from state A to state C of a Bohr atom, the wavelength of emitted radiation is $2000 A o$ and it becomes $6000 A o$ when the electron jumps from state B to state C. Then the…2025 · 24 Jan · Shift 1 · Q55 · MCQ
The energy E and momentum p of a moving body of mass m are related by some equation. Given that c represents the speed of light, identify the correct equation2025 · 24 Jan · Shift 2 · Q60 · MCQ
Choose the correct nuclear process from the below options [ p : proton, n : neutron, $e^{-}$ : electron, $e^{+}$ : positron, $v :$ neutrino, $\overset{v}{ˉ} :$ antineutrino]2025 · 28 Jan · Shift 1 · Q69 · MCQ
The frequency of revolution of the electron in Bohr's orbit varies with n, the principal quantum number as:2025 · 28 Jan · Shift 2 · Q60 · MCQ
The number of spectral lines emitted by atomic hydrogen that is in the 4th energy level, is2025 · 29 Jan · Shift 2 · Q53 · MCQ
The minimum energy required by a hydrogen atom in ground state to emit radiation in Balmer series is nearly :2024 · 1 Feb · Shift 1 · Q70 · MCQ
The radius of a nucleus of mass number 64 is 4.8 fermi. Then the mass number of another nucleus having radius of 4 fermi is $\frac{1000}{x}$ , where $x$ is .2024 · 1 Feb · Shift 1 · Q85 · Numerical
From the statements given below : (A) The angular momentum of an electron in $n^{th}$ orbit is an integral multiple of $ℏ$ . (B) Nuclear forces do not obey inverse square law. (C) Nuclear forces are spin dependent. (D) Nuclear…2024 · 1 Feb · Shift 2 · Q61 · MCQ
A particular hydrogen-like ion emits the radiation of frequency $3 \times 1 0^{15} Hz$ when it makes transition from $n = 2$ to $n = 1$ . The frequency of radiation emitted in transition from $n = 3$ to $n = 1$ is $\frac{x}{9} \times 1 0^{15} Hz$ …2024 · 1 Feb · Shift 2 · Q90 · Numerical
Which of the following nuclear fragments corresponding to nuclear fission between neutron $(_{0}^{1} n)$ and uranium isotope $(_{92}^{235} U)$ is correct :2024 · 4 Apr · Shift 1 · Q68 · MCQ
A hydrogen atom changes its state from $n = 3$ to $n = 2$ . Due to recoil, the percentage change in the wave length of emitted light is approximately $1 \times 1 0^{- n}$ . The value of $n$ is . [Given Rhc $= 13.6 eV, hc = 1242 eV nm, h = 6.6 \times 1 0^{- 34} J s$ …2024 · 4 Apr · Shift 1 · Q83 · Numerical
According to Bohr's theory, the moment of momentum of an electron revolving in $4^{th}$ orbit of hydrogen atom is:2024 · 4 Apr · Shift 2 · Q70 · MCQ
The disintegration energy $Q$ for the nuclear fission of $^{235} U \to^{140} Ce +^{94} Zr + n$ is $MeV$ . Given atomic masses of $^{235} U : 235.0439 u;^{140} Ce : 139.9054 u,^{94} Zr : 93.9063 u; n : 1.0086 u$ …2024 · 4 Apr · Shift 2 · Q85 · Numerical
An electron rotates in a circle around a nucleus having positive charge $Ze$ . Correct relation between total energy (E) of electron to its potential energy (U) is :2024 · 5 Apr · Shift 1 · Q76 · MCQ
If three helium nuclei combine to form a carbon nucleus then the energy released in this reaction is $\times 1 0^{- 2} MeV$ . (Given $1 u = 931 MeV / c^{2}$ , atomic mass of helium $= 4.002603 u$ …2024 · 5 Apr · Shift 1 · Q82 · Numerical
The angular momentum of an electron in a hydrogen atom is proportional to : (Where $r$ is the radius of orbit of electron)2024 · 5 Apr · Shift 2 · Q76 · MCQ
The shortest wavelength of the spectral lines in the Lyman series of hydrogen spectrum is $915 A o$ . The longest wavelength of spectral lines in the Balmer series will be $A o$ .2024 · 5 Apr · Shift 2 · Q87 · Numerical
The ratio of the shortest wavelength of Balmer series to the shortest wavelength of Lyman series for hydrogen atom is :2024 · 6 Apr · Shift 1 · Q80 · MCQ
Radius of a certain orbit of hydrogen atom is 8.48 $A o$ . If energy of electron in this orbit is $E / x$ . then $x =$ (Given $a_{0} = 0.529 A o$ , $E =$ energy of electron in ground…2024 · 6 Apr · Shift 1 · Q85 · Numerical
The longest wavelength associated with Paschen series is : (Given $R_{H} = 1.097 \times 1 0^{7} SI$ unit)2024 · 6 Apr · Shift 2 · Q73 · MCQ
Binding energy of a certain nucleus is $18 \times 1 0^{8} J$ . How much is the difference between total mass of all the nucleons and nuclear mass of the given nucleus:2024 · 8 Apr · Shift 1 · Q78 · MCQ
In an alpha particle scattering experiment distance of closest approach for the $α$ particle is $4.5 \times 1 0^{- 14} m$ . If target nucleus has atomic number 80 , then maximum velocity of $α$ -particle is $\times 1 0^{5} m / s$ …2024 · 8 Apr · Shift 1 · Q90 · Numerical
If $M_{0}$ is the mass of isotope $_{5}^{12} B, M_{p}$ and $M_{n}$ are the masses of proton and neutron, then nuclear binding energy of isotope is:2024 · 8 Apr · Shift 2 · Q68 · MCQ
In a hypothetical fission reaction $_{92} X^{236} \to_{56} Y^{141} +_{36} Z^{92} + 3 R$ The identity of emitted particles (R) is :2024 · 8 Apr · Shift 2 · Q77 · MCQ
The energy equivalent of $1 g$ of substance is :2024 · 9 Apr · Shift 1 · Q76 · MCQ
A star has $100%$ helium composition. It starts to convert three $^{4} He$ into one $^{12} C$ via triple alpha process as $^{4} He +^{4} He +^{4} He \to^{12} C + Q$ …2024 · 9 Apr · Shift 1 · Q87 · Numerical
A nucleus at rest disintegrates into two smaller nuclei with their masses in the ratio of $2 : 1$ . After disintegration they will move :2024 · 9 Apr · Shift 2 · Q64 · MCQ
The energy released in the fusion of $2 kg$ of hydrogen deep in the sun is $E_{H}$ and the energy released in the fission of $2 kg$ of $^{235} U$ is $E_{U}$ . The ratio $\frac{E _{H}}{E _{U}}$ is approximately:…2024 · 9 Apr · Shift 2 · Q71 · MCQ
A hydrogen atom in ground state is given an energy of $10.2 eV$ . How many spectral lines will be emitted due to transition of electrons?2024 · 9 Apr · Shift 2 · Q72 · MCQ
The radius of third stationary orbit of electron for Bohr's atom is R. The radius of fourth stationary orbit will be:2024 · 27 Jan · Shift 1 · Q71 · MCQ
In a nuclear fission process, a high mass nuclide $(A \approx 236)$ with binding energy $7.6 MeV /$ Nucleon dissociated into middle mass nuclides $(A \approx 118)$ , having binding energy of $8.6 MeV / Nucleon$ …2024 · 27 Jan · Shift 1 · Q85 · Numerical
The atomic mass of $_{6} C^{12}$ is $12.000000 u$ and that of $_{6} C^{13}$ is $13.003354 u$ . The required energy to remove a neutron from $_{6} C^{13}$ , if mass of neutron is $1.008665 u$ …2024 · 27 Jan · Shift 2 · Q68 · MCQ
If Rydberg's constant is $R$ , the longest wavelength of radiation in Paschen series will be $\frac{α}{7 R}$ , where $α =$ .2024 · 27 Jan · Shift 2 · Q90 · Numerical
The explosive in a Hydrogen bomb is a mixture of $_{1} H^{2},_{1} H^{3}$ and $_{3} Li^{6}$ in some condensed form. The chain reaction is given by $_{3} Li^{6} +_{0} n^{1} \to_{2} He^{4} +_{1} H^{3}_{1} H^{2} +_{1} H^{3} \to_{2} He^{4} +_{0} n^{1}$ …2024 · 29 Jan · Shift 1 · Q80 · MCQ
When a hydrogen atom going from $n = 2$ to $n = 1$ emits a photon, its recoil speed is $\frac{x}{5} m / s$ . Where $x =$ . (Use, mass of hydrogen atom $= 1.6 \times 1 0^{- 27} kg$ )2024 · 29 Jan · Shift 1 · Q84 · Numerical
Given below are two statements: Statement I : Most of the mass of the atom and all its positive charge are concentrated in a tiny nucleus and the electrons revolve around it, is Rutherford's model. Statement II : An atom is a spherical…2024 · 29 Jan · Shift 2 · Q78 · MCQ
Hydrogen atom is bombarded with electrons accelerated through a potential difference of $V$ , which causes excitation of hydrogen atoms. If the experiment is being performed at $T = 0 K$ , the minimum potential…2024 · 29 Jan · Shift 2 · Q85 · Numerical
The ratio of the magnitude of the kinetic energy to the potential energy of an electron in the 5th excited state of a hydrogen atom is :2024 · 30 Jan · Shift 1 · Q61 · MCQ
A electron of hydrogen atom on an excited state is having energy $E_{n} = - 0.85 eV$ . The maximum number of allowed transitions to lower energy level is .2024 · 30 Jan · Shift 1 · Q83 · Numerical
An electron revolving in $n^{th}$ Bohr orbit has magnetic moment $μ_{n}$ . If $μ_{n} \propto n^{x}$ , the value of $x$ is2024 · 30 Jan · Shift 2 · Q62 · MCQ
In a nuclear fission reaction of an isotope of mass $M$ , three similar daughter nuclei of same mass are formed. The speed of a daughter nuclei in terms of mass defect $Δ M$ will be :2024 · 30 Jan · Shift 2 · Q70 · MCQ
If the wavelength of the first member of Lyman series of hydrogen is $λ$ . The wavelength of the second member will be2024 · 31 Jan · Shift 1 · Q72 · MCQ
The mass defect in a particular reaction is $0.4 g$ . The amount of energy liberated is $n \times 1 0^{7} kWh$ , where $n =$ . (speed of light $= 3 \times 1 0^{8} m / s)$ 2024 · 31 Jan · Shift 1 · Q87 · Numerical
The mass number of nucleus having radius equal to half of the radius of nucleus with mass number 192 is :2024 · 31 Jan · Shift 2 · Q64 · MCQ
A nucleus has mass number $A_{1}$ and volume $V_{1}$ . Another nucleus has mass number $A_{2}$ and Volume $V_{2}$ . If relation between mass number is $A_{2} = 4 A_{1}$ , then $\frac{V _{2}}{V _{1}} =$ .2024 · 31 Jan · Shift 2 · Q87 · Numerical
The mass of proton, neutron and helium nucleus are respectively $1.0073 u, 1.0087 u$ and $4.0015 u$ . The binding energy of helium nucleus is :2023 · 1 Feb · Shift 1 · Q59 · MCQ
A light of energy $12.75 eV$ is incident on a hydrogen atom in its ground state. The atom absorbs the radiation and reaches to one of its excited states. The angular momentum of the atom in the excited state is $\frac{x}{π} \times 1 0^{- 17} eVs$ …2023 · 1 Feb · Shift 1 · Q65 · Numerical
An electron of a hydrogen like atom, having $Z = 4$ , jumps from $4^{th}$ energy state to $2^{nd}$ energy state. The energy released in this process, will be : (Given Rch = $13.6 eV$ ) Where R = Rydberg constant c =…2023 · 1 Feb · Shift 2 · Q64 · MCQ
Nucleus A having $Z = 17$ and equal number of protons and neutrons has $1.2 MeV$ binding energy per nucleon. Another nucleus $B$ of $Z = 12$ has total 26 nucleons and $1.8 MeV$ binding energy per nucleons. The…2023 · 1 Feb · Shift 2 · Q68 · Numerical
The energy levels of an hydrogen atom are shown below. The transition corresponding to emission of shortest wavelength is : Includes diagram2023 · 6 Apr · Shift 1 · Q59 · MCQ
The radius of fifth orbit of the $Li^{++}$ is $\times 1 0^{- 12} m$ . Take: radius of hydrogen atom $= 0.51 A o$ 2023 · 6 Apr · Shift 1 · Q62 · Numerical
A small particle of mass $m$ moves in such a way that its potential energy $U = \frac{1}{2} m ω^{2} r^{2}$ where $ω$ is constant and $r$ is the distance of the particle from origin. Assuming Bohr's quantization of momentum and…2023 · 6 Apr · Shift 2 · Q60 · MCQ
Experimentally it is found that $12.8 eV$ energy is required to separate a hydrogen atom into a proton and an electron. So the orbital radius of the electron in a hydrogen atom is $\frac{9}{x} \times 1 0^{- 10} m$ . The…2023 · 6 Apr · Shift 2 · Q64 · Numerical
For a nucleus $_{A}^{A} X$ having mass number $A$ and atomic number $Z$ A. The surface energy per nucleon $(b_{s}) = - a_{1} A^{2/3}$ . B. The Coulomb contribution to the…2023 · 8 Apr · Shift 1 · Q60 · MCQ
A nucleus with mass number 242 and binding energy per nucleon as $7.6 MeV$ breaks into two fragment each with mass number 121. If each fragment nucleus has binding energy per nucleon as $8.1 MeV$ , the total gain in…2023 · 8 Apr · Shift 1 · Q69 · Numerical
The waves emitted when a metal target is bombarded with high energy electrons are2023 · 8 Apr · Shift 2 · Q50 · MCQ
The ratio of wavelength of spectral lines $H_{α}$ and $H_{β}$ in the Balmer series is $\frac{x}{20}$ . The value of $x$ is .2023 · 8 Apr · Shift 2 · Q62 · Numerical
The angular momentum for the electron in Bohr's orbit is L. If the electron is assumed to revolve in second orbit of hydrogen atom, then the change in angular momentum will be2023 · 10 Apr · Shift 1 · Q60 · MCQ
If 917 $A o$ be the lowest wavelength of Lyman series then the lowest wavelength of Balmer series will be $A o$ .2023 · 10 Apr · Shift 2 · Q66 · Numerical
The energy of $He^{+}$ ion in its first excited state is, (The ground state energy for the Hydrogen atom is $- 13.6 eV)$ :2023 · 11 Apr · Shift 2 · Q48 · MCQ
A nucleus disintegrates into two nuclear parts, in such a way that ratio of their nuclear sizes is $1 : 2^{1/3}$ . Their respective speed have a ratio of $n : 1$ . The value of $n$ is .2023 · 11 Apr · Shift 2 · Q66 · Numerical
A $12.5 eV$ electron beam is used to bombard gaseous hydrogen at room temperature. The number of spectral lines emitted will be:2023 · 12 Apr · Shift 1 · Q58 · MCQ
A common example of alpha decay is $_{92}^{238} U ⟶_{90}^{234} Th +_{2} He^{4} + Q$ Given : $_{92}^{238} U = 238.05060 u$ , $_{90}^{234} Th = 234.04360 u$ …2023 · 12 Apr · Shift 1 · Q67 · Numerical
$_{92}^{238} A \to_{90}^{234} B +_{2}^{4} D + Q$ In the given nuclear reaction, the approximate amount of energy released will be: [Given, mass of $_{92}^{238} A = 238.05079 \times 931.5 MeV / c^{2},$ mass of $_{90}^{234} B = 234 \cdot 04363 \times 931 \cdot 5 MeV / c^{2},$ …2023 · 13 Apr · Shift 1 · Q55 · MCQ
The radius of $2^{nd}$ orbit of $He^{+}$ of Bohr's model is $r_{1}$ and that of fourth orbit of $Be^{3 +}$ is represented as $r_{2}$ . Now the ratio $\frac{r _{2}}{r _{1}}$ is $x : 1$ . The value of $x$ is …2023 · 13 Apr · Shift 1 · Q66 · Numerical
As per given figure $A, B$ and $C$ are the first, second and third excited energy levels of hydrogen atom respectively. If the ratio of the two wavelengths $($ i.e. $\frac{λ _{1}}{λ _{2}})$ is $\frac{7}{4 n}$ … Includes diagram2023 · 15 Apr · Shift 1 · Q66 · Numerical
A photon is emitted in transition from n = 4 to n = 1 level in hydrogen atom. The corresponding wavelength for this transition is (given, h = 4 $\times$ 10 $^{- 15}$ eVs) :2023 · 24 Jan · Shift 2 · Q60 · MCQ
The energy released per fission of nucleus of $^{240}$ X is 200 MeV. The energy released if all the atoms in 120g of pure $^{240}$ X undergo fission is $\times$ 10 $^{25}$ MeV. (Given $N_{A} = 6 \times 1 0^{23}$ )2023 · 24 Jan · Shift 2 · Q66 · Numerical
The wavelength of the radiation emitted is $λ_{0}$ when an electron jumps from the second excited state to the first excited state of hydrogen atom. If the electron jumps from the third excited state to the second orbit of the hydrogen…2023 · 25 Jan · Shift 1 · Q67 · Numerical
The energy levels of an atom is shown in figure. Which one of these transitions will result in the emission of a photon of wavelength 124.1 nm? Given (h = 6.62 $\times$ 10 $^{- 34}$ Js) Includes diagram2023 · 25 Jan · Shift 2 · Q65 · MCQ
Speed of an electron in Bohr's $7^{th}$ orbit for Hydrogen atom is $3.6 \times 1 0^{6} m / s$ . The corresponding speed of the electron in $3^{rd}$ orbit, in $m / s$ is :2023 · 30 Jan · Shift 1 · Q51 · MCQ
For hydrogen atom, $λ_{1}$ and $λ_{2}$ are the wavelengths corresponding to the transitions 1 and 2 respectively as shown in figure. The ratio of $λ_{1}$ and $λ_{2}$ is $\frac{x}{32}$ . The value of $x$ is … Includes diagram2023 · 31 Jan · Shift 1 · Q66 · Numerical
The radius of electron's second stationary orbit in Bohr's atom is R. The radius of 3rd orbit will be2023 · 31 Jan · Shift 2 · Q47 · MCQ
If the binding energy of ground state electron in a hydrogen atom is $13.6 eV$ , then, the energy required to remove the electron from the second excited state of $Li^{2 +}$ will be : $x \times 1 0^{- 1} eV$ . The…2023 · 31 Jan · Shift 2 · Q71 · Numerical
Choose the correct option from the following options given below :2022 · 24 Jun · Shift 1 · Q57 · MCQ
Nucleus A is having mass number 220 and its binding energy per nucleon is 5.6 MeV. It splits in two fragments 'B' and 'C' of mass numbers 105 and 115. The binding energy of nucleons in 'B' and 'C' is 6.4 MeV per nucleon. The energy Q…2022 · 24 Jun · Shift 1 · Q58 · MCQ
In Bohr's atomic model of hydrogen, let K, P and E are the kinetic energy, potential energy and total energy of the electron respectively. Choose the correct option when the electron undergoes transitions to a higher level :2022 · 24 Jun · Shift 2 · Q64 · MCQ
The momentum of an electron revolving in $n^{th}$ orbit is given by : (Symbols have their usual meanings)2022 · 25 Jul · Shift 1 · Q58 · MCQ
The magnetic moment of an electron (e) revolving in an orbit around nucleus with an orbital angular momentum is given by :2022 · 25 Jul · Shift 1 · Q59 · MCQ
Hydrogen atom from excited state comes to the ground state by emitting a photon of wavelength $λ$ . The value of principal quantum number ' $n$ ' of the excited state will be : ( $R :$ Rydberg constant)2022 · 25 Jul · Shift 2 · Q62 · MCQ
$\frac{x}{x + 4}$ is the ratio of energies of photons produced due to transition of an electron of hydrogen atom from its (i) third permitted energy level to the second level and (ii) the highest permitted energy level to the second…2022 · 25 Jul · Shift 2 · Q66 · Numerical
The ratio for the speed of the electron in the 3rd orbit of He+ to the speed of the electron in the 3rd orbit of hydrogen atom will be :2022 · 25 Jun · Shift 1 · Q58 · MCQ
In the hydrogen spectrum, $λ$ be the wavelength of first transition line of Lyman series. The wavelength difference will be "a $λ$ '' between the wavelength of $3^{rd}$ transition line of Paschen series and that of $2^{nd}$ …2022 · 26 Jul · Shift 1 · Q71 · Numerical
A nucleus of mass $M$ at rest splits into two parts having masses $\frac{M ^{'}}{3}$ and $\frac{2 M ^{'}}{3} (M^{'} < M)$ . The ratio of de Broglie wavelength of two parts will be :2022 · 26 Jul · Shift 2 · Q48 · MCQ
Two lighter nuclei combine to form a comparatively heavier nucleus by the relation given below : $_{1}^{2} X +_{1}^{2} X =_{2}^{4} Y$ The binding energies per nucleon for $\frac{2}{1} X$ and $_{2}^{4} Y$ are $1.1 MeV$ …2022 · 26 Jul · Shift 2 · Q61 · Numerical
A hydrogen atom in its ground state absorbs 10.2 eV of energy. The angular momentum of electron of the hydrogen atom will increase by the value of : (Given, Planck's constant = 6.6 $\times$ 10 $-$ 34 Js).2022 · 27 Jun · Shift 1 · Q58 · MCQ
A beam of monochromatic light is used to excite the electron in Li+ + from the first orbit to the third orbit. The wavelength of monochromatic light is found to be x $\times$ 10 $-$ 10 m. The value of x is .…2022 · 27 Jun · Shift 1 · Q63 · Numerical
Given below are two statements : Statement I : In hydrogen atom, the frequency of radiation emitted when an electron jumps from lower energy orbit (E1) to higher energy orbit (E2), is given as hf = E1 $-$ E2 Statement II : The jumping of…2022 · 27 Jun · Shift 2 · Q62 · MCQ
The Q-value of a nuclear reaction and kinetic energy of the projectile particle, Kp are related as :2022 · 28 Jun · Shift 1 · Q57 · MCQ
Find the ratio of energies of photons produced due to transition of an electron of hydrogen atom from its (i) second permitted energy level to the first level, and (ii) the highest permitted energy level to the first permitted level.2022 · 29 Jul · Shift 1 · Q64 · MCQ
$d_{1}$ and $d_{2}$ are the impact parameters corresponding to scattering angles 60 $^{\circ}$ and 90 $^{\circ}$ respectively, when an $α$ particle is approaching a gold nucleus. For d1 = x d2, the value of x will be …2022 · 29 Jun · Shift 1 · Q64 · Numerical
A hydrogen atom in ground state absorbs 12.09 eV of energy. The orbital angular momentum of the electron is increased by :2022 · 30 Jun · Shift 1 · Q59 · MCQ
A hydrogen atom in its first excited state absorbs a photon of energy x $\times$ 10 $-$ 2 eV and excited to a higher energy state where the potential energy of electron is $-$ 1.08 eV. The value of x is .2022 · 30 Jun · Shift 1 · Q66 · Numerical
The first three spectral lines of H-atom in the Balmer series are given $λ$ 1, $λ$ 2, $λ$ 3 considering the Bohr atomic model, the wave lengths of first and third spectral lines $(\frac{λ _{1}}{λ _{3}})$ …2021 · 16 Mar · Shift 1 · Q70 · Numerical
If an electron is moving in the nth orbit of the hydrogen atom, then its velocity (vn) for the nth orbit is given as :2021 · 17 Mar · Shift 1 · Q46 · MCQ
Which level of the single ionized carbon has the same energy as the ground state energy of hydrogen atom?2021 · 17 Mar · Shift 1 · Q60 · MCQ
The atomic hydrogen emits a line spectrum consisting of various series. Which series of hydrogen atomic spectra is lying in the visible region?2021 · 17 Mar · Shift 2 · Q46 · MCQ
A particle of mass m moves in a circular orbit in a central potential field U(r) = U0r4. If Bohr's quantization conditions are applied, radii of possible orbitals rn vary with $n^{\frac{1}{α}}$ , where $α$ is …2021 · 17 Mar · Shift 2 · Q69 · Numerical
Imagine that the electron in a hydrogen atom is replaced by a muon ( $μ$ ). The mass of muon particle is 207 times that of an electron and charge is equal to the charge of an electron. The ionization potential of this hydrogen atom will be…2021 · 18 Mar · Shift 1 · Q48 · MCQ
A nucleus of mass M emits $γ$ -ray photon of frequency 'v'. The loss of internal energy by the nucleus is : [Take 'c' as the speed of electromagnetic wave]2021 · 20 Jul · Shift 1 · Q56 · MCQ
A nucleus with mass number 184 initially at rest emits an $α$ -particle. If the Q value of the reaction is 5.5 MeV, calculate the kinetic energy of the $α$ -particle.2021 · 22 Jul · Shift 2 · Q55 · MCQ
In the given figure, the energy levels of hydrogen atom have been shown along with some transitions marked A, B, C, D and E. The transitions A, B and C respectively represent : Includes diagram2021 · 24 Feb · Shift 1 · Q58 · MCQ
According to Bohr atomic model, in which of the following transitions will the frequency be maximum?2021 · 24 Feb · Shift 2 · Q60 · MCQ
The wavelength of the photon emitted by a hydrogen atom when an electron makes a transition from n = 2 to n = 1 state is :2021 · 25 Feb · Shift 2 · Q59 · MCQ
From the given data, the amount of energy required to break the nucleus of aluminium $_{13}^{27}$ Al is x $\times$ 10 $-$ 3 J. Mass of neutron = 1.00866 u Mass of proton = 1.00726 u Mass of Aluminium nucleus =…2021 · 25 Jul · Shift 2 · Q68 · Numerical
A particular hydrogen like ion emits radiation of frequency 2.92 $\times$ 1015 Hz when it makes transition from n = 3 to n = 1. The frequency in Hz of radiation emitted in transition from n = 2 to n = 1 will be :2021 · 26 Aug · Shift 1 · Q52 · MCQ
If $λ$ 1 and $λ$ 2 are the wavelengths of the third member of Lyman and first member of the Paschen series respectively, then the value of $λ$ 1 : $λ$ 2 is :2021 · 26 Feb · Shift 1 · Q61 · MCQ
X different wavelengths may be observed in the spectrum from a hydrogen sample if the atoms are exited to states with principal quantum number n = 6 ? The value of X is .2021 · 27 Aug · Shift 2 · Q60 · Numerical
In Bohr's atomic model, the electron is assumed to revolve in a circular orbit of radius 0.5 $A o$ . If the speed of electron is 2.2 $\times$ 166 m/s, then the current associated with the electron will be …2021 · 27 Jul · Shift 1 · Q68 · Numerical
The K $α$ X-ray of molybdenum has wavelength 0.071 nm. If the energy of a molybdenum atoms with a K electron knocked out is 27.5 keV, the energy of this atom when an L electron is knocked out will be keV.…2021 · 27 Jul · Shift 2 · Q70 · Numerical
In a reactor, 2 kg of 92U235 fuel is fully used up in 30 days. The energy released per fission is 200 MeV. Given that the Avogadro number, N = 6.023 $\times$ 1026 per kilo mole and 1 eV = 1.6 × 10–19 J. The power output of the reactor is…2020 · 2 Sep · Shift 1 · Q40 · MCQ
In a hydrogen atom the electron makes a transition from (n + 1)th level to the nth level. If n >> 1, the frequency of radiation emitted is proportional to :2020 · 2 Sep · Shift 2 · Q56 · MCQ
Hydrogen ion and singly ionized helium atom are accelerated, from rest, through the same potential difference. The ratio of final speeds of hydrogen and helium ions is close to :2020 · 3 Sep · Shift 2 · Q46 · MCQ
The radius R of a nucleus of mass number A can be estimated by the formula R = (1.3 $\times$ 10–15)A1/3 m. It follows that the mass density of a nucleus is of the order of : (Mprot. $≅$ Mneut $≃$ 1.67 $\times$ 10–27 kg)2020 · 3 Sep · Shift 2 · Q54 · MCQ
In the line spectra of hydrogen atoms, difference between the largest and the shortest wavelengths of the Lyman series is 304 $A 0$ . The corresponding difference for the Paschan series in $A 0$ is : …2020 · 4 Sep · Shift 1 · Q42 · Numerical
Find the Binding energy per neucleon for $_{50}^{120} S n$ . Mass of proton mp = 1.00783 U, mass of neutron mn = 1.00867 U and mass of tin nucleus mSn = 119.902199 U. (take 1U = 931 MeV)2020 · 4 Sep · Shift 2 · Q61 · MCQ
A particle of mass 200 MeV/c2 collides with a hydrogen atom at rest. Soon after the collision the particle comes to rest, and the atom recoils and goes to its first excited state. The initial kinetic energy of the particle (in eV) is $\frac{N}{4}$ …2020 · 5 Sep · Shift 1 · Q41 · Numerical
You are given that Mass of $_{3}^{7} L i$ = 7.0160u, Mass of $_{2}^{4} H e$ = 4.0026u and Mass of $_{1}^{1} H$ = 1.0079u. When 20 g of $_{3}^{7} L i$ is converted into $_{2}^{4} H e$ by proton capture, the energy liberated, (in kWh), is : [Mass of nucleon = 1…2020 · 6 Sep · Shift 1 · Q51 · MCQ
Given the masses of various atomic particles mp = 1.0072 u, mn = 1.0087 u, me = 0.000548 u, $m_{\overline{v}}$ = 0, md = 2.0141 u, where p $\equiv$ proton, n $\equiv$ neutron, e $\equiv$ electron, $\overline{v} \equiv$ antineutrino and d $\equiv$ …2020 · 6 Sep · Shift 2 · Q53 · MCQ
The time period of revolution of electron in its ground state orbit in a hydrogen atom is 1.6 $\times$ 10-16 s. The frequency of revolution of the electron in its first excited state (in s-1) is :2020 · 7 Jan · Shift 1 · Q43 · MCQ
The graph which depicts the results of Rutherford gold foil experiment with $α$ -particales is : $θ$ : Scattering angle Y : Number of scattered $α$ -particles detected (Plots are schematic and not to scale)2020 · 8 Jan · Shift 1 · Q55 · MCQ
The first member of the Balmer series of hydrogen atom has a wavelength of 6561 Å. The wavelength of the second member of the Balmer series (in nm) is:2020 · 8 Jan · Shift 2 · Q58 · Numerical
The energy required to ionise a hydrogen like ion in its ground state is 9 Rydbergs. What is the wavelength of the radiation emitted when the electron in this ion jumps from the second excited state to the ground state ?2020 · 9 Jan · Shift 2 · Q52 · MCQ
Radiation coming from transitions n = 2 to n = 1 of hydrogen atoms fall on He+ ions in n = 1 and n = 2 states. The possible transition of helium ions as they absorb energy from the radiation is :2019 · 8 Apr · Shift 1 · Q51 · MCQ
The ratio of mass densities of nuclei of 40Ca and 16O is close to :-2019 · 8 Apr · Shift 2 · Q70 · MCQ
Taking the wavelength of first Balmer line in hydrogen spectrum (n = 3 to n = 2) as 660 nm, the wavelength of the 2nd Balmer line (n = 4 to n = 2) will be :2019 · 9 Apr · Shift 1 · Q49 · MCQ
A He+ ion is in its first excited state. Its ionization energy is :-2019 · 9 Apr · Shift 2 · Q47 · MCQ
In Li+ +, electron in first Bohr orbit is excited to a level by a radiation of wavelength $λ$ . When the ion gets deexcited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are…2019 · 10 Apr · Shift 2 · Q51 · MCQ
Consider the nuclear fission Ne20 $\to$ 2He4 + C12 Given that the binding energy/ nucleon of Ne20, He4 and C12 are, respectively, 8.03 MeV, 7.07 MeV and 7.86 MeV, identify the correct statement -2019 · 10 Jan · Shift 2 · Q72 · MCQ
A hydrogen atom, initially in the ground state is excited by absorbing a photon of wavelength 980 $A \circ$ . The radius of the atom in the excited state, in terms of Bohr radius a0 will be : (hc = 12500 eV $A \circ$ …2019 · 11 Jan · Shift 1 · Q65 · MCQ
In a hydrogen like atom, when an electron jumps from the M-shell to the L-shell, the wavelength of emitted radiation is $λ$ . If an electron jumps from N-shell to the L-shell, the wavelength of emitted radiation will be:2019 · 11 Jan · Shift 2 · Q60 · MCQ
An excited He+ ion emits two photons in succession, with wavelengths 108.5 nm and 30.4 nm, in making a transition to ground state. The quantum number n, corresponding to its initial excited state is (for photon of wavelength $λ$ ,…2019 · 12 Apr · Shift 1 · Q68 · MCQ
The electron in a hydrogen atom first jumps from the third excited state to the second excited state and subsequently to the first excited state. The ratio of the respective wavelengths, $\frac{λ _{1}}{λ _{2}}$ , of the…2019 · 12 Apr · Shift 2 · Q50 · MCQ
Consider an electron in a hydrogen atom revolving in its second excited state (having radius 4.65 $A o$ ). The de-Broglie wavelength of this electron is :2019 · 12 Apr · Shift 2 · Q57 · MCQ
A particle of mass m moves in a circular orbit in a central potential field U(r) = $\frac{1}{2}$ kr2. If Bohr 's quantization conditions are applied, radii of possible orbitls and energy levels vary with quantum number n as :2019 · 12 Jan · Shift 1 · Q69 · MCQ
The energy required to remove the electron from a singly ionized Helium atom is $2.2$ times the energies required to remove an electron from Helium atom. The total energy required to ionize the Helium atom completely is :2018 · 15 Apr · Shift 1 · Q56 · MCQ
Muon ( $μ -$ ) is a negatively charged (|q| = |e|) particle with a mass m $μ$ = 200 me, where me is the mass of the electron and e is the electronic charge. If $μ -$ is bond to a proton to form a hydrogen like atom, identify the correct…2018 · 15 Apr · Shift 2 · Q69 · MCQ
An unstable heavy nucleus at rest breaks into two nuclei which move away with velocities in the ratio of 8 : 27. The ratio of the radii of the nuclei (assumed to be spherical) is :2018 · 15 Apr · Shift 2 · Q70 · MCQ
If the series limit frequency of the Lyman series is $u_{L}$ , then the series limit frequency of the Pfund series is:2018 · Shift 0 · Q69 · MCQ
It is found that if a neutron suffers an elastic collinear collision with deuterium at rest, fractional loss of its energy is pd; while for its similar collision with carbon nucleus at rest, fractional loss of energy is pc. The values of…2018 · Shift 0 · Q70 · MCQ
An electron from various excited states of hydrogen atom emit radiation to come to the ground state. Let $λ_{n}$ , $λ_{g}$ be the de Broglie wavelength of the electron in the nth state and the ground state respectively. Let $Λ_{n}$ …2018 · Shift 0 · Q71 · MCQ
Two deuterons undergo nuclear fusion to form a Helium nucleus. Energy released in this process is : (given binding energy per nucleon for deuteron = 1.1 MeV and for helium = 7.0 MeV)2017 · 8 Apr · Shift 1 · Q74 · MCQ
According to Bohr’s theory, the time averaged magnetic field at the centre (i.e. nucleus) of a hydrogen atom due to the motion of electrons in the nth orbit is proportional to : (n = principal quantum number)2017 · 8 Apr · Shift 1 · Q75 · MCQ
Imagine that a reactor converts all given mass into energy and that it operates at a power level of 109 watt. The mass of the fuel consumed per hour in the reactor will be : (velocity of light, c is 3×108 m/s)2017 · 9 Apr · Shift 1 · Q52 · MCQ
The acceleration of an electron in the first orbit of the hydrogen atom (n = 1) is :2017 · 9 Apr · Shift 1 · Q53 · MCQ
Some energy levels of a molecule are shown in the figure. The ratio of the wavelengths r = $λ_{1}$ / $λ_{2}$ , is given by: Includes diagram2017 · Shift 0 · Q68 · MCQ
A hydrogen atom makes a transition from n = 2 to n = 1 and emits a photon. This photon strikes a doubly ionized lithium atom (z = 3) in excited state and completely removes the orbiting electron. The least quantum number for the excited…2016 · 9 Apr · Shift 1 · Q55 · MCQ
As an electron makes a transition from an excited state to the ground state of a hydrogen - like atom/ion :2015 · Shift 0 · Q43 · MCQ
The radiation corresponding to $3 \to 2$ transition of hydrogen atom falls on a metal surface to produce photoelectrons. These electrons are made to enter a magnetic field $3 \times 1 0^{- 4} T .$ If the radius of the larger circular…2014 · Shift 0 · Q48 · MCQ
Hydrogen $(_{1} H^{1})$ , Deuterium $(_{1} H^{2})$ , singly ionised Helium $(_{2} H e^{4})^{+}$ and doubly ionised lithium $(_{3} L i^{6})^{++}$ all have one electron…2014 · Shift 0 · Q50 · MCQ
In a hydrogen like atom electron make transition from an energy level with quantum number $n$ to another with quantum number $(n - 1)$ . If $n >> 1,$ the frequency of radiation emitted is proportional to :2013 · Shift 0 · Q51 · MCQ
A diatomic molecule is made of two masses $m_{1}$ and $m_{2}$ which are separated by a distance $r .$ If we calculate its rotational energy by applying Bohr's rule of angular momentum quantization, its energy will be given by: ( $n$ is an…2012 · Shift 0 · Q46 · MCQ
Assume that a neutron breaks into a proton and an electron. The energy released during this process is : (mass of neutron $= 1.6725 \times 1 0^{- 27} k g,$ mass of proton $= 1.6725 \times 1 0^{- 27} k g,$ mass of electron $= 9 \times 1 0^{- 31} k g$ …2012 · Shift 0 · Q47 · MCQ
Hydrogen atom is excited from ground state to another state with principal quantum number equal to $4.$ Then the number of spectral lines in the emission spectra will be :2012 · Shift 0 · Q48 · MCQ
Energy required for the electron excitation in $L i^{++}$ from the first to the third Bohr orbit is :2011 · Shift 0 · Q54 · MCQ
A nucleus of mass $M + Δ m$ is at rest and decays into two daughter nuclei of equal mass $\frac{M}{2}$ each. Speed of light is $c .$ The speed of daughter nuclei is2010 · Shift 0 · Q53 · MCQ
A nucleus of mass $M + Δ m$ is at rest and decays into two daughter nuclei of equal mass $\frac{M}{2}$ each. Speed of light is $c .$ The binding energy per nucleon for the parent nucleus is $E_{1}$ and that for the daughter nuclei is $E_{2} .$ …2010 · Shift 0 · Q54 · MCQ
The above is a plot of binding energy per nucleon $E_{b},$ against the nuclear mass $M; A, B, C, D, E, F$ correspond to different nuclei. Consider four reactions : $(i) A + B \to C + ε (ii) C \to A + B + ε (iii) D + E \to F + ε (i v) F \to D + E + ε,$ … Includes diagram2009 · Shift 0 · Q50 · MCQ
The transition from the state $n = 4$ to $n = 3$ in a hydrogen like atom result in ultra violet radiation. Infrared radiation will be obtained in the transition from :2009 · Shift 0 · Q52 · MCQ
Suppose an electron is attracted towards the origin by a force $\frac{k}{r}$ where $^{'} k^{'}$ is a constant and $^{'} r^{'}$ is the distance of the electron from the origin. By applying Bohr model to this system, the radius of the $n^{t h}$ orbital…2008 · Shift 0 · Q58 · MCQ
This question contains Statement- 1 and Statement- 2. Of the four choices given after the statements, choose the one that best describes the two statements: Statement- 1: Energy is released when heavy nuclei undergo fission or light nuclei…2008 · Shift 0 · Q59 · MCQ
If $M_{O}$ is the mass of an oxygen isotope $_{8} O^{17}$ , $M_{p}$ and $M_{N}$ are the masses of a proton and neutron respectively, the nuclear binding energy of the isotope is2007 · Shift 0 · Q63 · MCQ
Which of the following transitions in hydrogen atoms emit photons of highest frequency ?2007 · Shift 0 · Q66 · MCQ
When $_{3} L i^{7}$ nuclei are bombarded by protons, and the resultant nuclei are $_{4} B e^{8}$ , the emitted particles will be2006 · Shift 0 · Q101 · MCQ
If the binding energy per nucleon in $_{3}^{7} L i$ and $_{2}^{4} H e$ nuclei are $5.60 M e V$ and $7.06 M e V$ respectively, then in the reaction $p +_{3}^{7} L i \to 2_{2}^{4} H e$ energy of proton must be2006 · Shift 0 · Q103 · MCQ
An alpha nucleus of energy $\frac{1}{2} m v^{2}$ bombards a heavy nuclear target of charge $Z e$ . Then the distance of closest approach for the alpha nucleus will be proportional to2006 · Shift 0 · Q98 · MCQ
A nuclear transformation is denoted by $X (n, α) 73 L i .$ Which of the following is the nucleus of element $X$ ?2005 · Shift 0 · Q117 · MCQ
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? Includes diagram2005 · Shift 0 · Q118 · MCQ
An $α$ -particle of energy $5 M e V$ is scattered through $18 0^{\circ}$ by a fixed uranium nucleus. The distance of closest approach is of the order of2004 · Shift 0 · Q123 · MCQ
The binding energy per nucleon of deuteron $(_{1}^{2} H)$ and helium nucleus $(_{2}^{4} H e)$ is $1.1 M e V$ and $7 M e V$ respectively. If two deuteron nuclei react to form a single helium nucleus, then the energy…2004 · Shift 0 · Q124 · MCQ
The wavelengths involved in the spectrum of deuterium $(_{1}^{2} D)$ are slightly different from that of hydrogen spectrum, because2003 · Shift 0 · Q119 · MCQ
If the binding energy of the electron in a hydrogen atom is $13.6 e V,$ the energy required to remove the electron from the first excited state of $L i^{++}$ is2003 · Shift 0 · Q120 · MCQ
Which of the following atoms has the lowest ionization potential ?2003 · Shift 0 · Q121 · MCQ
In the nuclear fusion reaction $_{1}^{2} H +_{1}^{3} H \to_{2}^{4} H e + n$ given that the repulsive potential energy between the two nuclei is $\sim 7.7 \times 1 0^{- 14} J$ , the temperature at which the gases must be heated to initiate the…2003 · Shift 0 · Q123 · MCQ
If $13.6 e V$ energy is required to ionize the hydrogen atom, then the energy required to remove an electron from $n = 2$ is2002 · Shift 0 · Q135 · MCQ