Assertion : Half of the ring is uniformly positively charged and other half uniformly negatively charged. Then, electric field is zero at centre. Then , electric field is zero at centre.

Reason : At the centre of uniformly charged ring, electric field is zero.

Explanation

If we select two identical small segments of the ring that lie at the two ends of diameter of the ring, then electric field of these two segments will cancel cach other. And in the same way we can understand that electric field will be zero due to complete ring