Question

A student is holding a plastic comb that is carrying an overall negative charge. The student brings the comb NEAR a metal plate that has no charge (neutral). Which of these BEST describes an effect of holding the comb NEAR the metal plate?

A) Excess electrons from the metal plate are transferred to the comb.
B) The comb becomes positively charged, and the metal plate becomes negatively charged.
C) The electric field of the comb causes electrons in the metal plate to move away from the comb.
D) The electric field of the comb causes protons in the metal plate to move away from the comb.

Answer 1

When holding a negatively charged comb near a neutral metal plate, the electric field of the comb causes electrons in the metal plate to move away from the comb.

Step-by-step explanation:

When a student holds a negatively charged plastic comb near a neutral metal plate, the electric field of the comb causes the free electrons in the metal plate to move away from the comb. The negative charge on the comb repels the electrons in the metal plate, creating a region with a deficit of electrons near the comb and a region with an excess of electrons at the far end of the plate.

This effect is known as polarization, where equal but opposite charges separate. The answer to the question is C) The electric field of the comb causes electrons in the metal plate to move away from the comb.