ch 5 electric charges L2

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law of charge conservation

net zero charge is produced by any process e.g. in static electricity, total charge still adds up to zero

metal

good conductors, electrons are loosely bonded to nucleus so they can move

insulator

electrons are tightly bonded to nucleus, large resistance

semiconductor

very few free electrons, used for transistors

electric induction

charge/polarization can be induced on a neutral object by a charged object e.g. positive glass rod and neutral piece of paper

symbol for grounding

the force calculated by coulomb's law is

force between stationary point charges

coulomb’s law

F = 1/4πε x q1q2/r₁₂² in the direction of r

ε depends on

medium

force direction is

along the line joining the two charges and depends on like v unlike charges

with multiple point charges, total force is

vector sum of all individual forces (need both magnitude and direction)

test charge

positive infinitesmally small charge

electric induction in insulator vs metal

in insulator, the electrons move but still constrained, just pointing in the direction of the charged object

in metal, the electrons move freely “charging” the whole object kinda

what is happening here