Question

A -17 nC charge is located at the origin.

a- What is the strength of the electric field at the position (x,y)=(0cm,5.0cm)?

b- What is the strength of the electric field at the position (x,y)=(−5.0cm,−5.0cm)?

c-What is the strength of the electric field at the position (x,y)=(−5.0cm,5.0cm)?

Answer 1

Q = -17 * 10^-9 C

Solution

Position of points A, B and C are (0m,0.05 m), ( -0.05m,-0.05m) and (-0.05m and +0.05m)

Electric field E = kq/r²

E = kq/(x²+y²)

At point A

E_a= 9.x10⁹ x (-17x10^-9)/(0² + 0.05²)

= - 61200 N/C along y axis

At point B

E_b = 9.x10⁹ x (-17x10^-9)/[(-0.05² )+ (-0.05²)]

= - 30600 N/C along BO

At point C

E_c = 9.x10⁹ x (-17x10^-9)/[(-0.05² )+ 0.05²]

= - 30600 N/C along CO

(it is equal in magnitude of E at point B but different in direction by 90 degree)