Yes, there are mock tests available with a varying level of difficulty for different subjects. These mock tests are designed to help students assess their knowledge and preparation level for various subjects. They are particularly useful for competitive exams like NDA (National Defence Academy).

Benefits of Mock Tests:
- Mock tests provide an opportunity for students to practice and become familiar with the exam pattern, time management, and question types.
- They help in identifying strengths and weaknesses in different subjects.
- Mock tests help students gauge their level of preparedness and readiness for the actual exam.
- They provide a realistic exam-like experience, reducing anxiety and nervousness on the exam day.

Varying Level of Difficulty:
Mock tests are often designed with a varying level of difficulty to cater to students with different levels of preparation. This ensures that students can challenge themselves and progressively improve their performance. The difficulty levels can be categorized as follows:

1. Easy Level:
- These mock tests consist of basic and fundamental questions to assess the student's understanding of the subject.
- They help build a strong foundation and boost confidence.

2. Medium Level:
- These tests include questions that require moderate application of concepts and problem-solving skills.
- They evaluate the student's ability to apply knowledge in different scenarios.

3. Difficult Level:
- These mock tests contain complex and challenging questions that test the student's in-depth knowledge and analytical thinking.
- They help in identifying areas that require further improvement and advanced understanding.

Subject-Specific Mock Tests:
Mock tests are available for various subjects, including:

1. Mathematics:
- Mock tests for mathematics cover topics like algebra, geometry, trigonometry, calculus, etc.
- They assess the student's mathematical skills, problem-solving abilities, and numerical aptitude.

2. English:
- Mock tests for English evaluate the student's comprehension, grammar, vocabulary, and communication skills.
- They include reading passages, grammar-based questions, and vocabulary exercises.

3. General Knowledge:
- Mock tests for general knowledge assess the student's awareness of current affairs, history, geography, science, etc.
- They help in improving knowledge about various subjects and enhancing overall awareness.

Conclusion:
Mock tests with varying levels of difficulty for different subjects are an excellent tool for exam preparation. They provide students with a comprehensive evaluation of their strengths and weaknesses and help them improve their performance. Students can find such mock tests on EduRev, an online educational platform that offers a wide range of study materials and practice resources for various competitive exams, including NDA.