Question

The figure below shows a proton and an electron separated by a distant d. Point Pis a distance d/4 from the leftmost charge. If d is equal to 4 nm, what is the magnitude of the net electric field at point P, and which way does it point? proton d/4 P electron 5.1E9 N/C, to the right 5.1E9 N/C, to the left O 7.2E9 N/C, to the right 1.6E9 N/C, to the left 1.6E9 N/C, to the right

Answer 1

Separation between proton and electron, d = 4 nm

Distance of the point P from proton, r1 = d/4 = 1 nm = 1 x 10^-9 m

Distance of the point P from electron, r2 = 3d/4 = 3 nm = 3 x 10^-9 m

Electric field at the point P due to proton,

E1 = 1/4πε₀ q/r1² = 9 x 10⁹ x 1.6 x 10^-19/( 1 x 10^-9 )² = 1.44 x 10⁹ N/C

Electric field at the point P due to proton,

E1 = 1/4πε₀ q/r2² = 9 x 10⁹ x 1.6 x 10^-19/( 3 x 10^-9 )² = 0.16 x 10⁹ N/C

Total electric field at the point P is E = E1 + E2 = 1.44 x 10⁹ + 0.16 x 10⁹ = 1.60 x 10⁹ N/C

Total electric field at the point P is E = 1.60 x 10⁹ N/C and it acts to the right