Introduction:
The IIT JAM (Joint Admission Test for M.Sc.) is a national level entrance exam conducted by the Indian Institutes of Technology (IITs) for admission to various postgraduate programs, including Mathematics. It is essential for candidates to have a clear understanding of the exam pattern and marking scheme to perform well in the examination. In this context, let's discuss the marking scheme for the IIT JAM Mathematics paper.

Marking Scheme:
The IIT JAM Mathematics paper follows a specific marking scheme to evaluate the candidates' performance. It is crucial for candidates to be aware of this scheme to strategize their attempt accordingly.

Positive Marking:
The marking scheme for the IIT JAM Mathematics paper involves positive marking, which means that candidates receive marks for correct answers. The details regarding positive marking are as follows:

- For one-mark multiple-choice questions (MCQs), candidates are awarded one mark for each correct answer.
- For two-mark MCQs, candidates receive two marks for each correct response.
- For numerical answer type (NAT) questions, one or two marks are awarded for each correct answer, as mentioned in the question.

Negative Marking:
While there is positive marking in the IIT JAM Mathematics paper, negative marking is also applicable. Negative marking is a penalty for incorrect answers and plays a significant role in the overall score. The negative marking scheme is as follows:

- For one-mark MCQs, 1/3 (one-third) mark is deducted for each incorrect answer.
- For two-mark MCQs, 2/3 (two-thirds) marks are deducted for each wrong response.
- However, there is no negative marking for incorrect answers in the NAT section.

Impact of Negative Marking:
The negative marking scheme in the IIT JAM Mathematics paper has a significant impact on the overall score. It discourages candidates from guessing answers without proper knowledge and understanding of the concepts. Candidates need to be cautious while attempting MCQs and should only mark the answer if they are reasonably confident about its correctness. Guesswork can lead to a deduction of marks, which can significantly affect the final score.

Conclusion:
In the IIT JAM Mathematics paper, there is a marking scheme that includes both positive and negative marking. Candidates receive marks for correct answers, but incorrect answers result in the deduction of marks. It is crucial for candidates to be aware of this marking scheme and strategize their attempt accordingly to maximize their score.