The National Testing Agency (NTA) on Tuesday cancelled the NEET-UG exam a little over a week after it was conducted for 22.05 lakh candidates on May 3.  The cancellation this time is unique — while allegations of malpractices and paper leaks have surfaced before, this is the first time that the NTA is cancelling the exam in its entirety. NEET-UG, the entrance exam for undergraduate medical admissions, is the largest exam that the NTA conducts in terms of the number of candidates who appear on a single day and in a single shift. On May 7, the NTA received information about alleged malpractices surrounding the NEET-UG exam that was held on May 3. Sources in the NTA said that the allegations were about a PDF file that was circulating with questions, and they flagged the matter to law enforcement agencies on May 8. Since details about the document had surfaced four days after the exam, there was a need to verify if the document was in fact in circulation before the exam, sources said.…