The radius of electron's second stationary orbit in Bohr's atom is R. The radius of the third orbit will be

(a) 3 R                    (b) 2.25 R
(c) 9 R                    (d) $\frac{\mathrm{R}}{3}$

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Bohr's model of atom
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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 $\mathrm{K}=\frac{1}{2}{\mathrm{mv}}^{2}$ of the electron in C.G.S. system is equal to

(a) $\frac{1}{2}\frac{{\mathrm{Ze}}^{2}}{\mathrm{r}}$                             (b) $\frac{1}{2}\frac{{\mathrm{Ze}}^{2}}{{\mathrm{r}}^{2}}$
(c) $\frac{{\mathrm{Ze}}^{2}}{\mathrm{r}}$                                 (d) $\frac{{\mathrm{Ze}}^{2}}{{\mathrm{r}}^{2}}$

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Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

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In any Bohr orbit of the hydrogen atom, the ratio of kinetic energy to potential energy of the electron is
(a) 1/2                    (b) 2
(c) $-1/2$                (d) – 2

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Bohr's model of atom
High Yielding Test Series + Question Bank - NEET 2020

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The spectral series of the hydrogen spectrum that lies in the ultraviolet region is the

(a) Balmer series                 (b) Pfund series
(c) Paschen series                (d) Lyman series

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Spectral series
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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

(a) P to Q (b) Q to R
(c) R to S (d) R to G

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Spectral series
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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
(a) 1.89 eV                (b) 2.55 eV
(c) 12.09 eV              (d) 12.75 eV

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Bohr's model of atom
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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

(a) 1, 4, 6                      (b) 4, 5, 6
(c) 1, 2, 3                      (d) 1, 2, 3, 4, 5, 6

Concept Questions :-

Spectral series
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When a hydrogen atom is raised from the ground state to an excited state

(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

Concept Questions :-

Various atomic model
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The ratio of the kinetic energy to the total energy of an electron in a Bohr orbit is
(a) – 1                (b) 2
(c) 1 : 2              (d) None of these

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Bohr's model of atom
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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
(a) 13.6 eV                      (b) 4.53 eV
(c) 3.4 eV                        (d) 1.51 eV

Concept Questions :-

Bohr's model of atom