Summary Electric fields notes

Electric Fields Two Charges examples - Electric Field Strength Gravitational vs Electric F

Field lines out of positive charge • creates net electric field between + and - charge ↳ the amount of force per unit positive charge (NC-1) similarities differen
E-E
+ arrows show direction of the if F- ma and Q-It, then E - 19 so • both obey inverse • one inclu

force that a small positive +→ - base unit = ¥95s-2 = Kgms-3A-1 square law the other

test charge will experience. + both have infinite • gravitatio

Field lines into negative charge
① F " .
⊕ p...- + F = repulsion range attract,

r-distance between q and Q repel and

F = 0192 = 410, 09 Example -
#Eo rz
• two positive charges = no net electric field between them →Fg Fg Fe
Fe
due to charges repelling each other. ② Electric field strength around point charge: +
proton +
o.im....p...ro,

- focusing on small a

sub Fike, into E-E proton = + charge (mass of p
+ t
÷ by q is same r-o-1m

then E=
QQ ÷ a Fe = ,q = (9×109) (1.6
as × I
¥0' rz
4TEor² 0
• Charged sphere and charge plate/wall. i. E- Qa x
4TEor q
Fe- 2.3×10-26N
+
E=
L

• Field lines leave and
+
YTEor²
L



c

+
enter at 90. we can see that
u



t
• Direction + → - • Calculate ratio of electrosta

Fe = 2-3 × 10-26 N
=
Fg 1- 86×10-62 N