Doug rubs a piece of fur on a hard rubber rod, giving the rod a negative charge. What happens?

• Protons are removed from the rod.

• Electrons are added to the rod.

• The fur is also charged negatively.

• The fur is left neutral.

• Negative ions added to the fur.

A repelling force must occur between two charged objects under which conditions?

• charges are of unlike signs

• charges are of like signs

• charges are of equal magnitude

• charges are of unequal magnitude

When a glass rod is rubbed with silk, which of the following statements best describes what happens?

• electrons are removed from the rod

• protons are removed from the silk

• the silk is charged positively

• the silk remains neutral

• positive ions are removed from the silk

When charging two objects by rubbing them together:

• neither may be a conductor.

• they must be made of different material.

• they will sometimes end up with both being positively charged.

• the heat produced by friction is a necessary part of this process.

• they must have different temperature.

Who was the first to determine the electron's charge?

• Franklin D. Faraday

• Coulomb E. Maxwell

• Millikan

An uncharged conductor is supported by an insulating stand. I pass a positively charged rod near the left end of the conductor, but do not touch it. The right end of the conductor will be:

• negative.

• positive.

• neutral.

• attracted.

• repulsed.

Of the following substances, which one contains the highest density of free electrons?

• hard rubber

• iron

• amber

• glass

• silk

Which of the following best characterizes electrical conductors?

• low mass density

• high tensile strength

• poor heat conductors

• total electric charge is zero

Which of the following best characterizes electrical insulators?

• charges on the surface don't move

• high tensile strength

• electric charges move freely

• good heat conductors

• low specific heat

If body P, with a positive charge, is placed in contact with body Q (initially uncharged), what will be the nature of the charge left on Q?

• must be equal in magnitude to that on P

• must be negative

• must be positive

• must be greater in magnitude than that on P

• must be negative and less in magnitude than that on P