Question

a 100 ohm wire is bent in the form of a semicircle with diameter.the resistance across diameter is

Answer 1

As we know, resistance can be measure using the following formula…

When we bend the 10 ohm resistance wire into a circle, the length of each of the branches in parallel is half of that of the original wire. So, using the above formula, we get resistance of each branch to be 5 ohms.

Now since the 2 branches are in parallel, the effective resistance across diametrically opposite ends AB can be calculated using the following formula…

So, 1/R(total)=1/5+1/51/R(total)=1/5+1/5

1/R(total)=2/51/R(total)=2/5

R(total)=5/2=2.5ohmsR(total)=5/2=2.5ohms

Answer: 2.5 ohms.