The radius of the second Bohr orbit for hydrogen atom is:

(Planck's Const. h = 6.6262 × 10–34 Js; mass of electron = 9.1091 × 10–31 kg; charge of electron e = 1.60210 ×10–19 C; permittivity of vaccum 0 = 8.854185 ×10–12 kg–1m–3A2)

1. 0.529 Å

2. 2.12 Å

3. 1.65 Å

4. 7.76 Å

Subtopic:  Bohr's Theory |
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According to Bohr's theory, what is the angular momentum of an electron located in the fifth orbit? 

1. 25hπ

2. 1.0hπ

3. 10hπ

4. 2.5hπ

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Given below are two statements:
Statement I:  h\(\)v = (E2-E1) absorbs a photon.
Statement II:  hv = (E2-E1) = emitted a photon.
 In the light of the above statements, choose the correct answer from the option given below:

1. Both Statement I and Statement II are true.
2. Both Statement I and Statement II are false.
3. Statement I is true but Statement II is false.
4. Statement I is false but Statement II is true.
Subtopic:  Bohr's Theory | Hydrogen Spectra |
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According to Bohr's atomic theory:

(A) Kinetic energy of the electron is  \(\mathrm{\propto {Z^2\over n^2}}\) 
(B) The product of velocity (v) of electron and principal quantum number \(\mathrm{(n), 'vn'\propto Z^2}.\)
(C) Frequency of revolution of the electron in an orbit is \(\mathrm{\propto {Z^3\over n^3}}.\)
(D)

Coulombic force of attraction on the electron is \(\propto \dfrac{\mathrm{z}^3}{\mathrm{n}^4}.\)

Choose the most appropriate answer from the options given below :

1. (C) Only

2. (A) Only

3. (A), (C) and (D) only

4. (A) and (D) only

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The speed of an electron in the 7th orbit is 3.6 x 106 m/s, the speed in 3rd orbit is-

1. 3.6 x 106 m/s
2. 8.4 x 106 m/s
3. 7.5 x 106 m/s
4. 1.8 x 106 m/s
Subtopic:  Bohr's Theory |
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The angular momentum of an electron in an orbit of radius \(\mathrm{R}\) in a hydrogen atom is directly proportional to ____.
 
1. \(\mathrm{R}\) 2. \(\dfrac{1}{R}\)
3. \(\dfrac{1}{\sqrt{R}}\) 4. \(\sqrt{R}\)
Subtopic:  Bohr's Theory |
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