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=12mv2 of the electron in C.G.S. system is equal to

(1) 12Ze2r                             

(2) 12Ze2r2

(3) Ze2r                                 

(4) Ze2r2

Subtopic:  Bohr's Model of Atom |
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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 

(1) P to Q

(2) Q to R

(3) R to S

(4) R to G

Subtopic:  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 
(1) 1.89 eV               

(2) 2.55 eV

(3) 12.09 eV             

(4) 12.75 eV

Subtopic:  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

Subtopic:  Spectral Series |
 55%
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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 
(1) 13.6 eV                     

(2) 4.53 eV

(3) 3.4 eV                       

(4) 1.51 eV

Subtopic:  Bohr's Model of Atom |
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Which of the following statements about the Bohr model of the hydrogen atom is false 

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

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

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

(4) Potential energy of electron in n = 2 orbit is less than that in n = 1 orbit

Subtopic:  Bohr's Model of Atom |
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The ratio of the frequencies of the long wavelength limits of Lyman and Balmer series of hydrogen spectrum is

(1) 27 : 5                   

(2) 5 : 27

(3) 4 : 1                     

(4) 1 : 4

Subtopic:  Spectral Series |
 56%
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Which of the following transitions in a hydrogen atom emits photon of the highest frequency

(1) n = 1 to n = 2               

(2) n = 2 to n = 1

(3) n = 2 to n = 6               

(4) n = 6 to n = 2

Subtopic:  Spectral Series |
 69%
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Which of the transitions in hydrogen atom emits a photon of lowest frequency (n = quantum number)
(1) n = 2 to n = 1             

(2) n = 4 to n = 3

(3) n = 3 to n = 1             

(4) n = 4 to n = 2

Subtopic:  Spectral Series |
 71%
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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)+e28πε0r and  -e24πε0r            (b) +8πε0e2r and -4πε0e2r
(c) -e28πε0r and -e24πε0r            (d) +e28πε0r and +e24πε0r

Subtopic:  Bohr's Model of Atom |
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