Electrostatics

Insulators are different than conductors in that insulators ____.

• do not contain electrons or protons 
•  do not contain any charge
• have a weaker affinity for electrons 
• do not allow charge to freely move 

Consider the conduction charging shown. 

• Electrons move from the insulating stand into the sphere.
• Protons move from the bar into the sphere.
• Electrons move from the charged metal bar into the sphere.
• Protons move from the sphere into the negatively charged bar.

A glass rod becomes positively charged when it is rubbed with silk. This net positive charge accumulates because the glass rod

• gains electrons
• loses electrons
• gains protons
• loses protons

Two electrically charged identical-sized metal spheres, A (charge of -4) and B (charge of +8). If the spheres are brought into contact, which sphere will have a net gain of electrons?

• both A and B
• neither
• only A
• only B

Two like charges

•  neutralize each other.
• repel each other. 
• must be neutrons. 
• attract each other.

The charge of an electron is 

• positive. 
• negative. 
• Electrons have no charge

An atom loses an electron.  What type of charge does it have now?

• positive
• negative

An atom gains an electron.  What type of charge does it have now?

• positive
• negative
• No charge

What direction are the electric field lines around an electron?

• towards the charge
• away from the charge

What direction are the electric field lines around a proton?

• towards the charge

• away from the charge