A petition charging that the D.C. Bar examination is "racially discriminatory" and irrelevant to the practice of law was dismissed by the D.C. Court of Appeals yesterday.

The judges on the three-member panel said the petition, filed in 1974 by 25 black persons who failed the bar exam, did not convince them that the bar test is purposefully racist. Associate Judges John W. Kern 3d, J. Walter Yeagley and retired Associate Judge Hubert B. Pair said they believe the "exam has a rational relationship to the practice of law in the District of Columbia."

In its decision yesterday the court did grant test reviews to all persons who failed the bar exams given in 1974 and February, 1975.

The decision to allow reviews of tests given in 1974 and February 1975, grew out of a request by Thomas C. Harper for review of a bar exam he failed in 1974 and when he scored 69.2 per cent. A passing grade is 70 per cent.

Harper, who included his request for a review in the petition charging that the exam is discriminatory, asked that he be allowed to invoke the Post Examination Review for his 1974 test.

This review procedure began in May, 1975, more than a year after Harper had failed the test. The court ruled yesterday that anyone who took the bar exam as early as February, 1974, is entitled to a review.

The D.C. corporation counsel had argued that if Harper was granted permission to have his test reviewed then other persons who failed the exam could legitimately ask that their tests be reviewed.

In addition to charges of discrimination, the petition filed by the 25 persons who failed the test in 1974, contended that they were denied "due process" because there was no review procedures for their tests.

In granting Harper and others review of their 1974 test scores the judges said they had remedied any violations of due process.

The court dismissed the petitioners 40-page argument that the bar exam contained "cultural bias against blacks as a group," and that it asked questions that "persons of white middle class background have become familiar with because of family background."

The three-judge panel said a sample of bar exam questions submitted by the petitioners appeared to be "neutral."

"(The questions) do not evident cultural bias . . . (or give) any group an unfair advantage in answering the examination over the remaining applicants," the judges wrote.