The frequency of X rays , gamma rays , ultraviolet rays are respectively n1 , n2 , n3 . Then : - A ) n2 > n1 > n3 , B ) n2 < n1 > n3 , C ) n2 < n1 < n3 , D ) None of these ,

1 ) The frequency of X rays , gamma rays , ultraviolet rays are respectively n1 , n2 , n3 . Then  : -

A )  n2 > n1 > n3  ,                                   B ) n2 < n1 > n3  ,

C ) n2 < n1 < n3  ,                                   D ) None of these ,

Correct Answer : -  A )  n2 > n1 > n3  ,

Because the wavelength and frequency order for electromagnetic waves is  : - 

 

2 ) Frequency of seconds pendulum is ?

A ) 0.5 hz ,                                               B ) 1.0 hz ,

C ) 2.5 hz ,                                               D ) None of these ,

Correct Answer : -  A ) 0.5 hz ,

 solution : -

t = 2 seconds ,

So frequency = f = 1 / t = 1 / 2 = 0.5 hz .

3 ) Which have longest wavelength : -

A )  radio waves ,            B ) r - rays ,

C )  X – rays ,                  D ) Cosmic rays ,

Correct Answer : -   A )  radio waves ,

 

4 ) The scattering angle for which the Compton shift in wavelength is equal to the Compton wavelength ?

A ) 0 degree ,                                          B ) 90 degree ,

C ) 120 degree ,                                              D ) 180 degree , ,

Correct Answer : - B ) 90 degree ,

Solution : -

Formula : -

Compton wavelength : -  ∆λ = h/mv   ,

Compton shift  : -  ∆λ = ( h/mv )( 1 – cosθ )  ,

So here we put    θ = 90 degree  ,  because  ( cos90 = 0 )

So ,

∆λ = ( h/mv )( 1 – 0 )  ,

∆λ = ( h/mv )   So , Compton wavelength and Compton shift becomes equal .

 

5 ) Critical angle of light passing from glass to air is minimum for . . . . . . . . . . . . . . . . ( blue ) .

 

6 )  Torque acting on a body determines ..........

A ) angular momentum ,                  B ) linear momentum ,    

C ) both of these ,                            D ) None of these ,

Correct Answer : -  A ) angular momentum ,

Now go to online quiz section and Physics Quiz 8 is uploaded related to these mcqs  , so check your preparation by this link : -

UG Online quizzes