Students, who took the re-examination of the All India Pre-Medical/Pre-Dental Entrance Test (AIPMT) in Lucknow, said Saturday's paper was tougher than the one they answered in May.
The AIPMT re-examination was conducted amid tight security measures at 67 centres in the capital of Uttar Pradesh, where about 40,000 candidates appeared for the test.
"Chemistry particularly was tough than the last time. However, I felt biology was easier," said Kartikeya Khanna, who took the exam at DPS near the Post Graduate Institute.
Another candidate, Aditya, agreed that the chemistry portion was difficult as compared to the physics questions
A large number of candidates said they have already secured admissions in other colleges but wrote the retest hoping to get a better college.
"I got admission in a college in Bengaluru but through AIPMT I might get a good college in UP so I decided to take a chance," said Ravi.
Earlier in the day, students were frisked with metal detectors and allowed entry only after a thorough checking. Many queued up at the centres much before the reporting time as per the guidelines announced by the CBSE.
There were reports that about two dozen candidates missed their exam as they reached the centre beyond the stipulated time. Parents were seen arguing with security personnel to allow their children to enter the centre but they turned down their requests.
Thousands of candidates across the country appeared for the re-test of the AIPMT amid tight security measures like pat downs before being allowed inside the centres.
The Central Board of Secondary Education (CBSE) has come up with stringent measures to deter use of unfair means in the re-test after the exam which was held on May 3 was scrapped by the Supreme Court over reports of massive irregularities.
The education board had also issued a strict guideline for the applicants and barred them from carrying mobile phones, calculator, watch, geometry box, pencil box, handbag, handkerchiefs, scarves and any extra clothing. Students were asked to come in slippers and loose clothing. They are not even allowed to carry pens.