The disc to be plated is connected to the A - VCE - SSCE Chemistry - Question 9 - 2005 - Paper 1

For the process of electroplating to occur, the disc should be connected to the negative terminal of the battery. This allows the metal ions in the electrolyte to gain electrons (reduction) and deposit onto the surface of the disc. In electroplating, the disc acts as the cathode where reduction occurs, resulting in the metal being plated onto it.