Answer:
Step-by-step explanation:
Radius of ring r = .05 m
Electric field due to a uniformly charged ring
E = k Q x / ( x² + r² )³/² ; Q is charge on the ring , x is distance of point from the center of the ring and r is radius of the ring
electric field due to first ring at middle point or at x = 7.5 cm
E = 9 x 10⁹ x 33 x 10⁻⁹ x 7.5 x 10⁻² / ( 7.5² + 5² )³/² x 10⁻³
= 9 x 10⁹ x 33 x 10⁻⁹ x 7.5 / ( 7.5² + 5² )³/² x 10⁻¹
= 9 x 10⁹ x 33 x 10⁻⁹ x 7.5 / 73.23
= 30.41 N/C
The same field will be created by the other ring at the middle point because charge on the ring is same in magnitude . Due to negative charge on the second ring , field due to both the rings will align in the same direction.
Total field = 2 x 30.41
= 60.82 N/C