questions - Difference between どこですか and どこにいますか/どこにあり ますか?

(1) 本はどこですか。

(2) 本はどこにありますか。

Unless I'm mistaken, both those sentences mean something like "where is the book", what's the difference between using です and あります to indicate position?

I wouldn't have said (2) for "where is the book" but in an exercise where the question was "where is the switch" and the answer "next to the door", the answer used にあります so I assumed it was also in the question. It made me wonder when it was better to use どこですか instead of どこにありますか.

(Also, if there's an error in my sentences don't just correct them, also give an explanation to my question please)

Answer

The verb ある is translated "be located", so there's usually little semantic difference between どこですか？ and どこにありますか？ This rule can be further extended to XはYにあります = XはYです for a thing X and location Y.

本は机の上にあります。 = 本は机の上です。 The book is on the desk.

ジョンは秋葉原にいます。 = ジョンは秋葉原です。 John is in Akihabara.

However, of course, the extended form ～にあります is required when it's not obvious that Y is a location name in this construction.

ロナルドはマクドナルドです。 Ronald is McDonald. / Ronald is at McDonald's.
→ ロナルドはマクドナルドにいます。 Ronald is at McDonald's.

Now, the pronoun どこ, unlike English where, can not only indicate a location but also a group, community or organization (as well as ここ・そこ・あそこ), thus also affected by the ambiguity in some context.

出版社はどこですか？ Who is the publisher? / Where is the publisher?

→ 出版社はどこにありますか？ Where is the publisher?