Question

Two 10-cm-diameter charged rings face each other, 23cm apart. The left ring is charged to -25nC and the right ring is charged to +25nC .
What is the magnitude of the electric field E? at the midpoint between the two rings?

What is the magnitude of the Force F on a -1.0nC charged placed at the midpoint?

Answer both to two significant figures

Thank you!

Answer 1

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Two 10-cm-diameter charged rings face each other, 25.0cm cm apart. Both rings are charged to + 30.0nC nC . What is the electric field strength at the midpoint between the two rings? at the center of the left ring?

By considering the symmetry, any field on the axis of the rings will be directed along the axis. and at the midpoint between the rings the field is zero.

At the center of either ring, there is no net field from the ring itself; the only field there comes from the other ring. The linear charge density on the ring is ? = Q/(2*?*r) C/m. The field magnitude from any element ds along the ring is dE = kc*?*ds/d