Figure shows two rings having charges Q and `- sqrt(5)Q`. Find potential difference a and B i.e. `(V_(A)-V_(B))`.

Explanation

`V_(A)=(KQ)/R+(K(-sqrt(5)Q))/sqrt((2R)^(2)+(R)^(2)), V_(B)=(K(-sqrt(5)Q))/(2R)+(K (Q))/sqrt((R)^(2)+(R)^(2))`
from above, we can esily find `V_(A)-V_(B)`.