Central Board Of Secondary Education [CBSE] — out of syllabus questions and inequality in different sets

Sir i am appearing this year for my class 10 board exams
I got jbb/5 series set 2 question paper in mine science exam that was conducted on 4 march.
In that paper question 30 (D) part contains a question which is not at all related to our syllabus
The question was
A wire of resistance 5ohm is bent in form of a closed circle. Find the resistance between two points at the ends of any diameter of the circle.
Our ncert do not contain any word which tells us how resistance is distributed in circle.
On the other hand in set 1 and 3 there was internal choice in that question as well as difficulty level of set2 was much more than 1 and the you are free to see response of students on set 2 question paper as well as other sets you will find that set2 was really hard as compared to other sets
Please resolve this query of question 30 part d.
And provide full credit to all those who attempted that question.