Two blocks A and B are connected by a spring made of a non conducting material. The blocks are placed on a non conducting smooth horizontal surface (see figure). The wall touching A is also non conducting. Block A carries a charge – q. There exists a uniform electric field of intensity `E_0` in horizontal direction, in the entire region. Find the value of minimum positive charge Q that we must place on block B and release the system so that block A subsequently leaves contact with the wall. Force constant of the spring is k. Neglect interaction between charges on the blocks.

Answer

`Q=(q)/(2)`