61. The maximum number of photo electrons released in photocell is independent of

1. 1. Nature of the cathode surface

   
   
   

   2. Frequency of incident ray

   
   
   

   3. Intensity of radiations incident on cathode surface

   
   
   

   4. None of the above

   
   
   

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   NA

   Correct Option: B

   NA

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62. When yellow light is incident on a surface no electrons are emitted while green light can emit. If red light is incident on the surface then

1. 1. No electrons are emitted

   
   
   

   2. Photons are emitted

   
   
   

   3. Electrons of higher energy are emitted

   
   
   

   4. Electrons of lower energy are emitted

   
   
   

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   NA

   Correct Option: A

   NA

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63. Nuclear forces are mediated by

1. 1. Proton

   
   
   

   2. Neutron

   
   
   

   3. Meson

   
   
   

   4. Electron

   
   
   

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   NA

   Correct Option: C

   NA

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64. The mass number of a nucleus is

1. 1. Always less than its atomic number

   
   
   

   2. Always more than its atomic number

   
   
   

   3. Some times more than and some times equal to its atomic number

   
   
   

   4. None of the above

   
   
   

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   NA

   Correct Option: C

   NA

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65. The nucleus of an atom consists of

1. 1. Electrons and protons

   
   
   

   2. Neutrons only

   
   
   

   3. Neutrons and protons

   
   
   

   4. Protons, electrons and neutrons

   
   
   

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   NA

   Correct Option: C

   NA

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