Introduction:
When preparing for the history optional subject in the UPSC exam, it is essential to practice mock tests to assess one's knowledge and improve performance. However, the question of whether to attempt these mock tests with an open book or under closed book conditions is subjective and depends on individual preferences and study strategies.

Open Book Mock Tests:
1. Accessibility to Reference Material:
- One advantage of attempting history optional mock tests with an open book is the availability of reference material.
- It allows candidates to refer to books, notes, and other sources to find relevant information and support their answers.
- This can be particularly helpful for complex or unfamiliar topics, enabling candidates to provide more accurate and comprehensive responses.

2. Developing Research Skills:
- Open book mock tests provide an opportunity to improve research skills.
- Candidates can learn to quickly find information, verify facts, and interpret various sources effectively.
- This skill is valuable not only for the exam but also for future academic and professional endeavors.

3. Testing Comprehensive Understanding:
- Open book mock tests can help evaluate a candidate's level of understanding and application of concepts.
- It allows candidates to showcase their ability to integrate information from different sources and critically analyze historical events and perspectives.
- This approach encourages a deeper understanding of the subject matter rather than relying solely on memorization.

Closed Book Mock Tests:
1. Enhancing Memory and Recall:
- Attempting history optional mock tests under closed book conditions can improve memory and recall abilities.
- Candidates are compelled to rely on their understanding and retention of concepts, facts, and events.
- This practice helps reinforce learning and strengthens memory recall during the actual exam.

2. Time Management Skills:
- Closed book mock tests simulate the actual exam environment, where candidates are not allowed to refer to any external sources.
- This helps develop time management skills, as candidates learn to answer questions within the given time frame without relying heavily on references.
- It trains candidates to prioritize important information and respond promptly.

3. Exam Preparedness:
- Attempting mock tests under closed book conditions provides a realistic exam experience.
- It helps candidates assess their level of preparedness and identify areas that require further improvement.
- This practice also helps in building confidence and reducing exam-related anxiety.

Conclusion:
Both open book and closed book mock tests have their own advantages and serve different purposes. It is advisable to incorporate a balanced approach while preparing for the history optional subject. Initially, candidates can attempt open book mock tests to enhance their understanding and research skills. As the exam approaches, they can gradually shift towards closed book mock tests to improve memory recall, time management, and exam readiness. Regular practice and self-assessment through mock tests will contribute to a comprehensive and effective preparation strategy for the history optional subject in the UPSC exam.