Two identical metal sphere a and b in contact find charge when a negative ebonite rod is kept near a
Bring a negatively charged ebonite rod close to metal spheres a and b in contact. As the rod is brought close to the sphere, the free electrons in the sphere move away due to repulsion and start piling up at the farther end. The near end becomes positively charged due to deficit of electrons. This process of charge stops when the net force on the free electrons inside the metal is zero.