Hewitt 22.5-22.6 hw

Coulomb's law is most similar to which of these laws?

• Archimedes' laws of hydrostatics
• Newton's law of gravity
• The law of electric potential
• The conservation of energy

Why are metals good conductors of both heat and electricity?

• The outer shell electrons in metals are free to move from atom to atom.
• The outer shell electrons in atoms vibrate in place and emit electromagnetic radiation that travels throughout the metal.
• The outer shell electrons in metals move with zero resistance, making all metals superconductors.
• The outer shell electrons in metals are tightly bound, making it easy for vibrations to move from one atom to the next.

Why are materials such as glass and rubber good insulators?

• Electrons are loosely bound to their atoms, making them good conductors of heat.
• Electrons are loosely bound to their atoms, making them poor conductors of heat.
• Electrons are tightly bound to their atoms, making them poor conductors of heat.
• Electrons are tightly bound to their atoms, making them good conductors of heat.

How does a semiconductor differ from a conductor or an insulator?

• A semiconductor has exactly half the resistance of a conductor and twice the resistance of an insulator.
• A semiconductor has exactly half the resistance of an insulator and twice the resistance of a conductor.
• A semiconductor is a good conductor of electric current but a poor conductor of heat.
• A semiconductor is neither a good conductor nor a good insulator - it has a middle range of resistivity.

What happens to electrons in any charging process?

• Electrons transfer from one place to another.
• Electrons stay in place as protons are transferred from one place to another.
• Electrons are destroyed.
• Electrons are created.

What kind of charging occurs when you slide your body across a plastic surface?

• Charging by friction occurs. Electrons move from a neutral object to a negatively charged object.
• Charging by friction occurs. Electrons are transferred when one object rubs against another.
• Charging by induction occurs. Electrons in one object push away electrons in the other object.
• Charging by touching occurs. Electrons move from a negatively charged object to a neutral object.

A glass marble is rubbed against a piece of silk. As a result the piece of fabric acquires extra electrons. What happens to the glass marble?

• The marble has lost the same number of electrons acquired by the piece of silk.
• The marble has acquired the same number of electrons acquired by the piece of silk.
• The marble acquires a positive charge and repels the piece of silk.
• The marble acquires a positive charge and attracts the piece of silk.
• More than one answer is correct

Consider the situation in the figure below, where two charged rods are placed a distance d on either side of an aluminum can. What does the can do?

• Rolls to the left
• Rolls to the right
• Stays still