56. In an atom the order of filling up of the orbitals is governed by

1. 1. Aufbau principle

   
   
   

   2. Heisenberg's uncertainly principle

   
   
   

   3. Hund's rule

   
   
   

   4. Pauli's exclusion principle

   
   
   

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   NA

   Correct Option: A

   NA

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57. The constituent particle of a nucleus in an atom are

1. 1. electron and proton

   
   
   

   2. proton and neutron

   
   
   

   3. electron and neutron

   
   
   

   4. electron, proton and neutron

   
   
   

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   NA

   Correct Option: B

   NA

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58. When spectral lines obtained from atomic spectra is placed in a magnetic field they are splitted into number of fine lines, this is called ..........

1. 1. Stark's effect

   
   
   

   2. Photoelectric effect

   
   
   

   3. Zeeman's effect

   
   
   

   4. None of these

   
   
   

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   NA

   Correct Option: C

   NA

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59. The number of unpaired electrons in carbon atom is

1. 1. 2

   
   
   

   2. 4

   
   
   

   3. 1

   
   
   

   4. 3

   
   
   

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   NA

   Correct Option: A

   NA

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60. The electronic configuration of atom / ion can be defined by which of the following ?

1. 1. Aufbau principle

   
   
   

   2. Pauli's exclusion principle

   
   
   

   3. Hund's rule

   
   
   

   4. All of the above

   
   
   

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   NA

   Correct Option: D

   NA

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