How many dwarf planets exist in our solar system? What are their names? How were they discovered?
As of now, about 200 small and quite large dwarf planets have been discovered. Ceres, Pluto, Eris, Haumea, Quaoar,Sedna and Orcus are some of them.
With advances in technology and instrumentation, it is discoveries galore for distant dwarf planets with perihelion at 100+ AU level.
Notable earlier and recent discoveries are the nearest-to-Sunr (asteroid reclassified as dwarf planet by IAU) Ceres (1801 AD), Pluto (1930), Haumea (2003), Eris and Makemake (2005), Quaoar, Sedna, Orcus...... The list is long, as found in wiki;s.
The important deficiency in the so-called dwarf planet is that its gravitational force is insufficient to clear its neighborhood of small space bodies around, by suction.