Chemistry teacher Anthony got irked as all students, barring two or there, got single digit marks in the test conducted by him yesterday.
Late in the evening, the students were asked to stand in a row, police said, adding, he thrashed them.
Several students had bruises on their back, they said.
Some students, who were seriously injured, fainted and were taken to a hospital, police said.
Parents thrashed the teacher as was being taken by police today.
A case has been registered against the teacher for beating the students, police said, adding, they would register the case against those who assaulted him if he gave a complaint.