In bringing an electron toward another electron , electrostatic potential energy of system : - A ) increase , B ) decrease , C ) remain same , D ) None of these ,

1 ) In bringing an electron toward another electron , electrostatic potential energy of system will : -

A ) increase ,                                                      B ) decrease ,

C ) remain same ,                                              D ) None of these ,

Correct Answer : -   A ) increase ,

V ∝ 1 / r .

So when distance decreases , electric potential will increases .

 

2 ) Some charge is given to conductor , their potential  . . . . . . . . throughout the conductor .

A ) increase ,                                                      B ) decreases ,

C ) remain same ,                                               D ) None of these ,

Correct Answer : -   C ) remain same ,

 

3 ) Electric potential is . . . . . . . , when line joining has two equal and opposite charges .

A ) finite ,                                                   B ) infinite ,

C ) zero ,                                                    D ) None of these ,

Correct Answer : -   C ) zero ,

When line joining has two equal and opposite charges  e.g  +2 q  and  -2 q  .  So , Electric potential will be zero .

 

4 ) Electric potential of earth is taken to be . . . . . . . . because earth is good conductor .

A ) finite ,                                                   B ) infinite ,

C ) zero ,                                                    D ) None of these ,

Correct Answer : -   C ) zero ,

 

5 ) Equal charges are given to two spheres of different radii .  The potential will be more on : -  smaller sphere .  

V = kq / r .

So , V ∝ 1 / r .

 

6 ) The electric potential at the surface  of an atomic nucleus ( z = 50 ) of radius  9 x 10 ^ ( - 15 ) m is : -

A ) 4 x 10 ^ 3 Volt  ,                                   B ) 8 x 10 ^ 6 Volt  , 

C ) 18 x 10 ^ 7  Volt  ,                                         D ) None of these ,

Correct Answer : -   B ) 8 x 10 ^ 6 Volt  , 

Solution : -

Formula : -

V = w / q  = k q / r . . . . . . . . . . . eq. 1

So , q = z e = 50 x 1.6 x 10 ^ ( - 19 ) .

and k = 9 x 10 ^ 9 .

So , put in Equation 1 : -

V = ( 9 x 10 ^ 9 x 50 x 1.6 x 10 ^ ( - 19 ) ) / ( 9 x 10 ^ ( - 15 ) ) .

V = 8 x 10 ^ 6 Volt  ,  Answer .

Now go to online quiz section and Physics Quiz 13 is uploaded related to these mcqs  , so check your preparation by this link : -

UG Online Quizzes