A wire that has resistance R is cut into two equal piece. The two parts are joined in parallel. What is the resistance of the combination?
As the wire is cut into two equal pieces. So resistance of each part is R/2.
The two parts are joined in parallel. So the equivalent resistance will be
1/Requivalent = 2/R + 2/R
1/Requivalent= 4/R
Requivalent = R/4