A small neutral Styrofoam ball is suspended by an insulating thread
PHYSICS · Single correct · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance
Problem
A small neutral Styrofoam ball is suspended by an insulating thread. A positively charged glass rod is held several centimeters away, and the ball accelerates toward the rod. Which of the following best explains the attractive interaction?
(a) Electrons leave the ball and move to the rod, giving the ball a net negative charge that is attracted to the positive rod.
(b) The positively charged rod causes the surrounding air molecules to polarize, and the resulting electric field pulls the ball toward the rod.
(c) Electrons inside the ball shift slightly toward the rod, creating an induced charge separation that results in a net attraction.
(d) Protons inside the ball are free to move and therefore migrate slightly toward the rod, producing an attractive force.