Multiple Choice - Electric Charges and Fields

How charges transfer when object is rubbed

• Physically scraping off electrons - friction

• Object losing electrons become positively charged and object gaining electrons become negatively charged

Vector nature of electric fields and electrical charges

• Electrical field lines have direction and magnitude

• Field lines point away from + towards -

• Magnetic field lines: away from north towards south

Behavior of electroscope when additional charge is near

• Charged object near electroscope causes leaves to move apart - induced charges

• If electroscope is grounded while near charged object, it becomes permanently charged

Coulomb's law

Conductors vs insulators

• Conductors: electrons can move freely

• Insulators: electrons are tightly packed

Conduction, induction, polarization

• Conduction: direct transfer of electrons by touch

• Induction: rearranging charges without touching

• Polarization: shifting electrons within atoms in insulators

Electrical forces

• Forces between charged particles can attract or repel

• Opposites attract, likes repel

• Proton and electron

What is the flow of electrons measured in?

(a)  

In which direction do electrons move?

• From positive to negative

• From negative to positive

Conventional current is from ______ to ______.

(a)