Furman guard Stephen Croone, who scored a career-best 40 points in his last game, was held to 11 points, all but two in the second half. Larry Wideman also scored 11 for the Paladins (5-7), who have lost three of four games.
William Gates Jr. led the Paladins with 13 points.
California, which opens Pac-12 play at Bay Area rival Stanford on Thursday night, took an early lead behind its best shooting effort of the season at 61 percent.
Cobbs, 18 of 49 (36.7 percent) since his 31-point effort against Dayton, was 9 of 13 against the Paladins. Wallace, 9 of 25 (36 percent) his previous two games, sank 8 of 10 shots against Furman.
The Bears led at halftime, 43-25, shooting 58 percent from the field, their second best shooting half of the season.
Cal played without starters Ricky Kreklow and Jabari Bird. Kreklow, a junior, broke his right hand during a practice before Christmas. Bird, a freshman averaging 11.9 points a game, suffered a sprained ankle in the Bears' 68-54 loss at Creighton last Sunday.
Powers, a redshirt senior, entered the game with two points in a combined 21 minutes on the season.
Furman held its only lead at 4-2, which California erased by scoring the next 11 points. The Bears went up by double digits in the first eight minutes and it was never close afterward.
Coach Mike Montgomery won his 118th game at Cal (666 overall) to move within a game of Pete Newell for fourth on the school's all-time win list.
The Bears improved to 43-6 at home in nonconference games under Montgomery, who ranks 27th on the all-time Division I wins list.