Aim: What is an Electric Field Aim: What is an Electric Field? Do Now: What does the word field mean to you?

What is an Electric Field? A region in space in which an electrostatic force acts on a charge Exists around every charged object Mapped by drawing field lines (indicate the direction of the electrostatic force an a + test charge placed in a field.) It is a vector quantity

Equation Magnitude is equal to the force exerted per unit charge at that point in the electric field. What does this translate to mathematically?

E=F/q Where: E is the magnitude of the electric field F is the magnitude of the force q is the magnitude of the charge

Units F is measured in Newtons q is measured in Coulomb’s What will E be measured in then? F/q = Newtons/Coulomb’s = E

What is the magnitude of the electrostatic force experienced by one elementary charge at a point in the electric field where the electric field intensity is 3.0 x 103 N/C?

Drawing Electric Field Lines + A B Point A is 1 meter from sphere, so E = 9 N/C Point B is 3 meters from sphere, so E = ?

E d Based on your answer from the previous slide, where is E stronger?

Charged conducting sphere inside + + + + + + + + + + + + +

Between 2 parallel charged plates - - - - - - - - B C A + + + + + + + + What is E for each point?

What is the Relationship between field strength and potential difference? Do Now: Fill out the scantron for the Winter Break Assignment HW: Quiz tomorrow on Coulomb’s Law and Electric Fields

Charged Particle Behavior - - - - - - - +q v + + + + + + + Curved path due to electric field on charged particle Older TV’s and inkjet printers use this technology

Electric Work Existing Electric Field F +q d Fe If we push a charge opposite the field direction, work is done WE = F·d Since W = ΔPE, the charge has more potential energy at the final location.

Relationship between Electric Field Strength and Electric Potential Difference V = W/q W = F·d for a constant Force (constant field) V = F·d/q F/q = E V = Ed