This is disputed.

Shulchan Arukh, Orach Chayyim 307:17:

> אָסוּר לִלְמֹד בְּשַׁבָּת וְיוֹם טוֹב, זוּלַת בְּדִבְרֵי תּוֹרָה;
> וַאֲפִלּוּ בְּסִפְרֵי חָכְמוֹת אָסוּר; וְיֵשׁ מִי שֶׁמַּתִּיר, וְעַל
> פִּי סְבָרָתוֹ מֻתָּר לְהַבִּיט באצטרלו''ב בְּשַׁבָּת, <small>
> וּלְהָפְכָהּ וּלְטַלְטְלָהּ כְּדִלְקַמָּן סי' ש''ח. </small>


My loose translation:

One should not learn anything on SHabbat except Torah related matters. Even studying books of wisdom (I assume this means "adages" or something similar?) is forbidden. But someone says that one may use a tool that astrologers use ( like a Zodiac chart?) on Shabbat (translation from *Ba'er Hetev*).

On the other hand, it seems that if the sole purpose of studying is for an exam that will occur after Shabbat, then, it seems quite obvious that you are preparing on Shabbat for a weekday. That's a separate prohibition.