Be clear about one thing before you start: the CSS written examination is not a multiple choice examination. The compulsory and optional papers are written papers, marked on how you argue, and no amount of objective practice substitutes for writing them.
Objective practice still earns its place, for two reasons. The MPT screening test is objective, and the recall that the written papers draw on — dates, articles of the constitution, institutions, treaties — is exactly what a question bank drills efficiently.
What objective practice is good for here
Use it for the factual base underneath the essays. A question that asks which article covers a particular right, or which year a treaty was signed, takes fifteen seconds to practise and would otherwise cost you a vague sentence in a written answer.
Use it to find holes. A run of wrong answers in one period of Pakistan's history is a specific thing to go and read about, which is more useful than a general feeling of being underprepared.
Do not use it as your main preparation. Reading, note-making and writing practice under time are what the written papers reward.
The screening test
The MPT is objective and it is the gate: candidates who do not clear it do not sit the written papers at all. It covers English, general knowledge, current affairs, Islamic studies, Pakistan affairs, everyday science, basic mathematics and computer literacy. That is close to the subject list above, which is why this page is the right place to prepare for it.
Confirm the current MPT composition and passing requirement on FPSC's own site before you plan around any particular split. It has been revised since it was introduced.
Current affairs for CSS is different
For most tests, current affairs means remembering what happened. For CSS it means being able to discuss why, on paper, at length. Use the objective questions to fix the facts — who, where, when, which agreement — and then read properly on the handful of issues you expect to write about.
Anything from the last year or two in any question bank should be checked against a current source. That applies here more than anywhere, because an examiner will notice.
Where to go next
The buttons above open the subject banks, each question with its answer and a written explanation. The CSS beginner's guide explains what the examination actually involves, which is worth reading first if you are new to it.