The device planted in the lecture theatre at the Federal College of Education (FCE) in Kano was discovered by a campus security guard and dismantled before causing any damage.
In April, attackers suspected of belonging the radical Boko Haram Islamist group killed roughly 20 people at the nearby Bayero University, Kano.
They set off bombs at a Sunday morning campus church service, then opened fire as worshippers tried to flee.
“This morning, something suspected to be an improvised explosive device has been successfully detected and detonated by the anti-bomb squad of the Nigeria police in the college,” said FCE spokesman Auwalu Mudi Yakasai in a statement.
He added that the exams would continue uninterrupted.
It was not immediately clear who planted the device, but Boko Haram, responsible for scores of attacks across northern and central Nigeria in recent months, has hit Kano repeatedly in the past.
The name Boko Haram, a combination of Hausa and Arabic, means “Western education is forbidden.”
Kano, Nigeria’s second most populous city, was the site of the group’s deadliest attack yet on January 20 when at least 185 people were killed in coordinated gun and bomb attacks.
The group has claimed the deaths of more than 1,000 people since mid-2009, and three of its presumed top leaders have been designated as global terrorists by the United States.