Assertion (A): Equal amounts of positive and negative charges are distributed uniformly on two halves of a thin circular ring as shown in the figure. The resultant electric field at the centre O of the ring is along OC. Reason (R): It is so because the net potential at O is not zero.
(A)If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(B)If both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of Assertion (A).
(C)If Assertion (A) is true but Reason (R) is false.✓ Correct
(D)If both Assertion (A) and Reason (R) are false.
Answer: (C)
Solution
Each element of the positively charged half and the diametrically opposite element of the negatively charged half produce fields that add in the same direction, so the resultant field at O points along OC (from the + half towards the − half) — A is true. However, the potentials of the two halves are equal and opposite, so the net potential at O is zero — R is false. Hence A is true, R is false.
CBSE Class 12 Board · 2024 · Single correct option
