# Q 2 p x y using the superposition principle find the

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#1 3 Q #2 P x y Using the superposition principle find the magnitude of the electric field at a point P in the gap. 1. bardbl vector E P bardbl = 3 Q ǫ 0 A 2. bardbl vector E P bardbl = Q 2 ǫ 0 A 3. bardbl vector E P bardbl = Q ǫ 0 A 4. bardbl vector E P bardbl = 0 5. bardbl vector E P bardbl = 3 Q 2 ǫ 0 A 6. bardbl vector E P bardbl = 4 Q ǫ 0 A 7. bardbl vector E P bardbl = 2 Q ǫ 0 A correct 8. bardbl vector E P bardbl = 5 Q ǫ 0 A 9. bardbl vector E P bardbl = Q ǫ 0 10. bardbl vector E P bardbl = Q 3 ǫ 0 A Explanation: According to the result of part 1, the electric field generated by plate #1 at P is E 1 = Q 2 ǫ 0 A directed along the positive x -axis. The field generated by plate #2 has a magni- tude E 2 = 3 Q 2 ǫ 0 A and it is directed along the positive x -axis also, since the charge is nega- tive. Therefore, the magnitudes add and we get E gap = Q 2 ǫ 0 A + 3 Q 2 ǫ 0 A = 2 Q ǫ 0 A . 008 10.0points Two large, parallel, insulating plates are charged uniformly with the same positive areal charge density + σ , which is the charge per unit area. What is the magnitude of the resultant elec- tric field E ? The permittivity of free space ǫ 0 = 1 4 π k e . 1. σ ǫ 0 between the plates, zero outside 2. σ 2 ǫ 0 between the plates, σ 2 ǫ 0 outside 3. σ 2 ǫ 0 between the plates, zero outside 4. 2 σ ǫ 0 between the plates, zero outside 5. Zero everywhere 6. σ ǫ 0 everywhere 7. Zero between the plates, 2 σ ǫ 0 outside 8. 2 σ ǫ 0 between the plates, 2 σ ǫ 0 outside 9. Zero between the plates, σ 2 ǫ 0 outside 10. Zero between the plates, σ ǫ 0 outside cor- rect Explanation: Each plate produces a constant electric field of E = σ 2 ǫ 0 directed away from the plate for positive charge density, and toward the plate for negative charge density. Between the two plates, the two fields cancel each other so that E net = 0. Outside the two plates, the fields add together, so that E net = σ ǫ 0 . 009(part1of2)10.0points
nguyen (ktn529) – Homework 04 – yao – (56120) 5 Q R radius Consider a solid conducting sphere of ra- dius R and total charge Q . Which diagram describes the E ( r ) vs r (electric field vs radial distance) function for the sphere? r R 0 1 r 2
nguyen (ktn529) – Homework 04 – yao – (56120)