An unmarried Northern Virginia woman, denied permission to take the state bar examination because she lives with a man, asked the Virginia Supreme Court yesterday to overturn the ruling as "arbitrary" and "unreasonable."

The bar applicant, Bonnie Cord, a 33-year-old lawyer for the Federal Energy Regulatory Administration in Washington, was blocked from taking the exam last March by Warren County Circuit Court Judge Duncan C. Gibb, who held that her living arrangement would "lower the public's opinion of the bar as a whole."

Cord's lawyer, Thomas V. Monahan of Winchester, yesterday called publicity about the case "unfortunate," but cited some of the news stories as proof that Gibb's ruling was "insappropriate."

"From the Washington Post on one end of a spectrum that I do not define to The New York Times. The Wall Street Journal and the Winchester Star on my own ultraconservative end of the spectrum, the public reaction to the court's ruling has been one of surprise," Monahan, told the three-judge panel.

He asked the judges to bypass normal appeal procedures and issue an order requiring Judge Bibb to certify Cord as having good character, a requirement for taking the bar exam. "I don't think the interests of the bar would be a written opinion by this court," he said.

However, Monahan said, if the court does not require Gibb to issue a certificate of good character immediately, it should accept Cord's petition for an appeal of the ruling. The panel is expected to rule today. If it rejects the peitition for an immediate order but accepts the case for appeal, a final ruling could be delayed for a year or more.

Stressing that his officer is required by law to defend Judge Gibb against a potential order requiring him to act, Assistant State Attorney General John hardin Young told the panel it should not bypass normal appeal procedures.

"We have not argued that Ms. Cord is unfit to take the bar examination," Young said. ". . . We consciously made no moral statement regarding Ms Cord's behavior or o nthe merits of the judge's decision. . . .

"Our sole argument on behalf of the judge is that since the General Assembly made the judge's decision discretionary," he cannot be required to change it without a full appeal of the case.

Monahan and the Virginia chapter of the American Civil Liberties Union, in a friend-of-the-court brief, argued that Gibb ignored evidence that Cord's living arrangement is well known in the community of Linden in Warren County, where she lives, and has not affected her good reputation there.

A three-lawyer panel that investigated Cord's background for the court recommended by a vote of 2 to 1 that Gibb certify her to take the exam.