A metal wire has a resistance of `60Omega`. It is cut into three equal lengths. Find the equivalent resistance when two parts are connected in parallel and the third part is in series with them.

Explanation

Resistance of wire = `60Omega`
When cut in three equal parts.
Resistance of each part=` (60)/(3)=r= 20 Omega`

Resistance between A and C is given by
`(1)/(R)= (1)/(20)+(1)/(20)= (1+1)/(20)= (2)/(20)= (1)/(10)`
`R.= 10Omega`
Now resistance between A and B is `R.. = 10+20= 30Omega`