Two identical pith balls supported by insulating threads hang side by side and close together,as shown below.
One is positively charged;the other is neutral.We can conclude that
A)all field lines leaving the positively charged pith ball end on the neutral pith ball.
B)some of the field lines leaving the positively charged pith ball end on the neutral pith ball.
C)none of the field lines leaving the positively charged pith ball end on the neutral pith ball.
D)positive charge is transferred along the field lines until both balls have equal charges.
E)positive charge is transferred along the field lines until both balls hang along vertical lines.

Question

Two identical pith balls supported by insulating threads hang side by side and close together,as shown below. 
One is positively charged;the other is neutral.We can conclude that
A)all field lines leaving the positively charged pith ball end on the neutral pith ball. 
B)some of the field lines leaving the positively charged pith ball end on the neutral pith ball. 
C)none of the field lines leaving the positively charged pith ball end on the neutral pith ball. 
D)positive charge is transferred along the field lines until both balls have equal charges. 
E)positive charge is transferred along the field lines until both balls hang along vertical lines.

Quizplus · Accepted Answer

As the positively charged pith ball has excess positive charge, this implies it has more protons than electrons. This gives it an electric field that spreads out in all directions. Since the neutral pith ball is nearby, it experiences the electric field and becomes polarized. Electrons are repelled from the neutral ball and they accumulate on the far side of it, away from the positively charged pith ball. This creates an excess of negative charge on the far side of the neutral ball, which attracts positive charge from the positively charged pith ball. Electric field lines emanating from the positively charged pith ball pass through the region occupied by the neutral ball, causing some fraction of these field lines to end on the neutral ball. Therefore, some of the field lines leaving the positively charged pith ball end on the neutral pith ball.

Two Identical Pith Balls Supported by Insulating Threads Hang Side