John Cooper, 12 hours after leading Arizona State to its biggest football victory of the year, yesterday was introduced as Ohio State's new football coach by Athletic Director Jim Jones.

Cooper's Sun Devils beat Air Force, 33-28, in the Freedom Bowl Wednesday night.

The announcement marked the end of a six-week search for a successor to Earle Bruce. Bruce, 81-26-1 in nine years at Ohio State, was fired Nov. 16 by Ohio State President Edward Jennings. Bruce had replaced Woody Hayes, who coached the Buckeyes for 28 years.

Cooper said he was sorry to leave Arizona State, but "when a job like Ohio State opens up, you've got to take advantage of the opportunity. I went after the job, there's no question about that."

Cooper, 50, had a 25-9-2 record in three years at Arizona State, including a victory over Michigan in last year's Rose Bowl and a 7-4-1 mark this season. He coached eight years at Tulsa with a 57-31 mark.

His first-year salary will be $98,000. He is guaranteed $240,000 from sources such as radio and television contracts.

Howard Coach Willie Jeffries has said he considered himself a contender for the job . . .

Jim Cavanaugh, on Maryland's football coaching staff six years and last season's offensive coordinator, has been named wide receivers coach at North Carolina under Mack Brown.

Cavanaugh, 39, has been an assistant coach 14 years, including five as Maryland's running back coach before being named offensive coordinator last season.