BSc student Rahul Yadav of local Bipin Bihari College beat up his teacher when he objected to them copying in examination on March 17, police said.
A case was registered against Rahul, who is also the president of the students' union, and some of his friends who were involved in assaulting the teacher, principal of the college Dr M M Pandey said.
Superintendent of Police, Jhansi City, Rajesh Kumar Rai said Rahul has been arrested and a hunt was on to nab the remaining accused.