The maximum dragging force on a falling sphere of 9.8 N is ?

1 )   The maximum dragging force on a falling sphere of 9.8 N is : -

A ) 4.8 N ,                                        B )  9.8 N ,

C )  18.6 N ,                                                D ) None of these ,

Correct Answer : -   B )  9.8 N ,

Solution : -

Given data : -

·         F = 9.8 N   ,

·         g = 9.8 m/s2     ,

 Formula : -

Ø    F = mg  .    { For finding mass of object }  ,

Ø    9.8 = m * 9.8   ,

Ø    m  =   1 kg .

  Now we find the dragging force ( weight )   of an object ,  So :-

Ø    w = mg   ,

Ø    w =  1 * 9.8     ,

Ø    w = 9.8  N   .    Answer .

 

2 )  Dimensions of spring constant ( k )  is  : -

A ) M T^(-1)   ,                                              B ) M T^(-2)   ,

C ) M T^(-3)   ,                                                 D ) None of these ,

Correct Answer : -   B ) M T^(-2)   ,

Solution : -

Formula : -

 F =k x    ,

Ø   k = F / x    ,

Ø   k = N / m   ,

Ø   k = (kg m s^(-2)) / m   ,

Ø   k =  kg s^(-2),  S.I units    ,

 So  , dimensions will be : -

Ø   k = M T^(-2)   ,      Answer   .

 

3 )   LED ( light emitting diode ) coverts ………………….. ,

A ) Electrical energy into light energy ,                B ) light energy into electrical energy ,

C ) Mechanical energy into light energy ,             D ) None of these ,

Correct Answer : -   A ) Electrical energy into light energy ,

4 )   The bonding in inert gas crystal is due to ………………………… ,

A ) Vand waal forces ,                               B ) Both ,

C ) dipole dipole ,                                      D ) None of these ,

Correct Answer : -  A ) Vand waal forces ,

5 )  Power  : -    P = F .v        ,

 

6 )   Momentum : -     

   F = ∆p / ∆t  ,

Ø     So  ,     p  =  F . t  ,

 

Now go to online quiz section and check your preparation by this link : -

UG Online quizzes