Only 30.11 per cent of students passed the test in the Science stream as the results, declared by the Bihar School Examination Board Chairman Anand Kishore, showed.
The results were dismal in the Arts stream too where a meager 37 per cent of the examinees could pass the test.
In the Commerce stream, however, the pass percentage was 73.76.
Nearly 13 lakh students had appeared for the Plus-Two examination which was held between February 14 and February 25 this year.
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While state education minister Ashok Choudhary hailed the successful conduct of a cheating-free examination, the BJP blamed the poor pass percentage on the education system run by the Nitish Kumar government.
In 2015, the Science stream pass percentage was 89.32 and 67.06 per cent in 2016, but plunged to 30.11 per cent this year.
In the Commerce stream, 90.55 per cent students passed in 2015 and 80.87 per cent in 2016, but slided to 73.76 per cent this year.
Last year, Arts topper Ruby Roy in a TV interview after publication of results had pronounced political science as "Prodikal science" which, according to her, was related to cooking.
Later, a probe had revealed a racket in the state's class 12 examination.