Q1 Automobile is less common word the American still use this word, car on the other hand is more common word and is generally used around the English speaking nations. Q2 Fiddle is another one which describes a string instrument which is played with a bow but Fiddle also is a term used to describe some who cheats i.e (he has fiddled with the accounts) Violin is more common word is now used to describe this instrument.

Automobile, edifice and conflagration are older words and not used in conversation You will still meet 'automobile' eg The Automobile Association

All answers in regard to American English 1) A car means a 'sedan'- so not a truck or SUV. We don't used automobile in regular conversation, but it is used in print in regard to vehicles. 2) The main difference btwn fiddles and violins is the type of music played on it- fiddles are more country and folksy than violins, which are classical and 'nicer' instruments. 3) Edifices are large buildings. The word is used figuratively more than literally, such as- the president stood out as an edifice among low-lying men. 4) Conflagrations are big, destructive fires.