Question

A charge of 8 mC is located at the origin. Calculate the work done in taking a small charge of −2 × 10⁻⁹ C from a point P (0, 0, 3 cm) to a point Q (0, 4 cm, 0), via a point R (0, 6 cm, 9 cm).

Answer 1

Charge located at the origin, q = 8 mC= 8 × 10⁻³ C

Magnitude of a small charge, which is taken from a point P to point R to point Q, q₁ = − 2 × 10⁻⁹ C

All the points are represented in the given figure.

Point P is at a distance, d₁ = 3 cm, from the origin along z-axis.

Point Q is at a distance, d₂ = 4 cm, from the origin along y-axis.

Potential at point P,

Potential at point Q,

Work done (W) by the electrostatic force is independent of the path.

Therefore, work done during the process is 1.27 J.