The section where students were supposed to mark their Mathematics responses had 'Physics' written on it and vice versa. This led to confusion among the students.
"The invigilator consulted his seniors after we pointed out the problem. About 15 minutes later, we were asked to mark the answers according to the serial numbers of the questions," said Debkalpa Goswami, an examinee.
Professor T S Natarajan, organising chairman for JEE-2010, IIT-Madras, said, "The error was noticed immediately after the start of the morning session."
"Students at all centres were instructed to ignore the subject headings and mark their answers in the ORS sheet according to the question numbers in the question paper," Natarajan said.
The entrance comprised two papers with each paper having questions on physics, chemistry and mathematics.
The first paper started at 9 am while the second paper was held between 2 pm and 5pm.
The students qualifying the test will be eligible for admission into the B.Tech programmes at 15 IITs, ISM Dhanbad and IT-BHU. The results will be announced on May 26.