A body is charged with a uniform charge density p = 3.1 nC/m³. A spherical cavity is created inside the body with radius R = 0.58 m (all the charges that were inside the sphere were taken out of the body). Before the cavity was created the electric potential at point O (at the center of the cavity) was 40 = 102 V. What is the potential at O after creating the cavity?

At a certain distance from a charged particle, the magnitude of the electric field is 500 V/m and the electric potential is 3.00 kV. (a) What is the distance to the particle? (b) What is the magnitude of the charge?

A filament running along the x axis from the origin to x = 80.0 cm carries electric charge with uniform density. At the point P with coordinates (x = 80.0 cm, y = 80.0 cm), this filament creates electric potential 100 V. Now we add another filament along the y axis, running from the origin to y = 80.0 cm, carrying the same amount of charge with the same uniform density. At the same point P, is the electric potential created by the pair of filaments (a) greater than 200 V, (b) 200 V, (c) 100 V, (d) between 0 and 200 V, or (e) 0?

Figure P26.80 shows a wire with uniform charge per unit length = 2.25 nC/m comprised of two straight sections of length d = 75.0 cm and a semicircle with radius r = 25.0 cm. What is the electric potential at point P, the center of the semicircular portion of the wire? FIGURE P26.80