Two oppositely charged, identical insulating spheres, each 50.0 cm in diameter and carrying a uniformly distributed charge of magnitude 250 ?C, are placed 1.00 m apart center to center ( Fig. P23.56 ).?

(a) If a voltmeter is connected between the nearest points (a and b) on their surfaces, what will it read?

(b) Which point, a or b, is at the higher potential? How can you know this without any calculations?

Figure P23.56 + a V b