Static Electricity - Mission SE4 Detailed Help

A neutral metal sphere is touched by a negatively charged metal rod. As a result, the sphere will become charged by ____.

Methods of Charging:
There are three methods of charging that are commonly discussed in a static electricity unit - charging by friction, charging by conduction (or contact), and charging by induction.

Tribelectric charging ( Charging by friction) usually involves the rubbing of two objects together.

Charging by conduction (or contact) involves the touching of a charged object to a neutral object.

Charging by induction involves bringing a charged object near to but not touching a neutral object in order to polarize the object and then charging it by momentarily connecting it to a ground.