Question

A resistance of 10 ohm is bent in the form of a closed circle . What is the effective resistance between the two at the ends of any diameter of this circle?

Answer 1

When a resistance is bent in a circle, the resistors are are connected in parallel.

Each of the resistors (the 2 parallel resistors of the circle) have a resistance of 10 ohms.

So we get the following-

R_eq = R1 x R2 / R1R2 (where R_eq is equivalent resistance in parallel connections)

OR

1/R_p =1/R1 + 1/R2 ( where Rp is resistance in parallel )

1/R_p = 1/10 + 1/10

1/R_p = 2/10

R_p = 10/2

R_p = 5 ohms