1 ) When a hydrogen atom is raised from the ground state to an excited state , so . . . . . . . . . A ) P.E decreases and K.E increases , B ) P.E increases and K.E decreases , C ) P.E and K.E both are equal , D ) None of these ,

1 ) When a hydrogen atom is raised from the ground state to an excited state , so . . . . . . . . .

A ) P.E decreases and K.E increases ,

B ) P.E increases and K.E decreases ,

C ) P.E and K.E both are equal ,

D ) None of these ,

Correct Answer : -  B ) P.E increases and K.E decreases ,

 

2 ) The process by which the potential barrier of the depletion region can be increased or decreased  is called . . . . . . . . . . . . . . ,

A ) biasing  ,                                              B ) modulation ,

C ) doping ,                                               D ) None of these ,

Correct Answer : -  A ) biasing  ,

 

3 )  The process of combining low frequency signals with high frequency carriers is called  ……………….. ,

A ) amplification ,                                                         B ) modulation ,

C ) rectification ,                                                 D ) None of these ,

Correct Answer : -  B ) modulation ,

 

4 ) The minimum energy required to remove an electron from the metal surface is called work function of metal .

 

5 ) The total energy of H - atom in ground state is . . . . . . . . . . . .  ( -13.6 ev ) .

 

6 ) A laser device produces amplification in the . . . . . . . . . . . . . (  U.V or visible region of spectrum ) .

 

7 ) Thermodynamic scale or absolute scale is a temperature scale which is . . . . . . . . . . . . . . ( independent ) of the nature of working substance .

 

8 )  ( Metastable state ) . . . . . . . . . . . . of atom or nucleus is a state that has longer life time  than ordinary excited state .