A point charge -3q is positioned at point (2, -1, 3) of a Cartesian coordinate system. A test point charge 2q is placed at point (3, 0, 4). Which of the following is the unit vector in the direction of the force acting on the test charge? All the coordinates are in meters.
Options

Question

A point charge -3q is positioned at point (2, -1, 3) of a Cartesian coordinate system. A test point charge 2q is placed at point (3, 0, 4). Which of the following is the unit vector in the direction of the force acting on the test charge? All the coordinates are in meters.

Options

G1 Physics · Accepted Answer

Step 1: Form the displacement vector 𝐫 = 𝐫₂ - 𝐫₁ and its magnitude r. Step 2: Coulomb's vector law is 𝐅 = [1/(4πε₀)](q₁q₂/r³) 𝐫. The sign of q₁q₂ fixes whether the force is along or opposite 𝐫. Step 3: Substitute the given coordinates/charges and reduce the components. Final: Option D.