The potential of the electrostatic field of a point charge at a distance of 10 cm from it is 150 V.

The potential of the electrostatic field of a point charge at a distance of 10 cm from it is 150 V. What is the value of the potential at a distance of 25 cm?

Data: r1 (initial distance from the charge) = 10 cm (in SI r1 = 0.1 m); φ1 (first potential) = 150 V; r2 (considered distance from the charge) = 25 cm (in SI r2 = 0.25 m).

Since the field potential can be determined by the formula: φ = 1 / (4 * Π * ε0) * q / r, the field potential at a distance of 25 cm can be expressed from the equality: q / (4 * Π * ε0) = φ1 * r1 = φ2 * r2, whence φ2 = φ1 * r1 / r2.

Calculation: φ2 = 150 * 0.1 / 0.25 = 60 V.

Answer: The field potential is 60 V.