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Electric Field. Electric Field – The space around an electrically charged body which exerts a force on a charge placed within the field. The field exerts the force. -. +. +q. +q. Direction of field = direction of force on a positive test charge in the field.
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Electric Field – The space around an electrically charged body which exerts a force on a charge placed within the field. The field exerts the force.
- + +q +q Direction of field = direction of force on a positive test charge in the field
Electric Field Strength – force exerted per unit charge in the field E = Fon q/q units: N/C E does not depend on the test charge; only on the charges producing the field
E due to a single point charge = kQ/r2 =(kqQ/r2)/q E = F/q = (1/(4Πε0))Q/r2 Fon q = qE direction: same as field for +q opposite field for -q
Field produced by 2 charges 10 cm 10 cm X Q2 = +50 μC Q1 = -50 μC E @ X? Resultant E = 9.0 x 107 N/C to the right What if both charges = +50 μC? E = 0
10 cm 10 cm X Q2 = +50 μC Q1 = -50 μC Net force on -5 μC charge @X? F = Eq = (9.0 x 107) (5 x 10-6) = 450 N to the left
Q2 = +50 μC 10 cm Q1 = -50 μC 10 cm E @ origin? 6.4 x 107 N/C @ 45° down from +x axis
+Q d +Q d (√2) kQ/d2 @ 45° down from –x axis E @ origin? If put –q charge @ origin, force on this charge? (√2) kQq/d2 @ 45° up from +x axis
X s s +Q +Q s E @ X?
+Q s s +Q +Q s E @ center of triangle?