Hindu parents & unmarried children living together.

(1) Is this an hindu undivided family under law?

(2) Father purchasing property from his own funds but in the name of 19 years dependent son because father already owns a house in his(father's) name in Delhi & second house is not allowed under law in delhi in the name of father.Is the property so acquired in the name of son be a joint family propertyafter the death of father?