Question

A wire of resistance 12 ohm per metre is bent to form a complete circle of radius 10 c.m.the resistance between its two diametrically opposite point A and B

Answer 1

the circumference is C = 2pi*r. Make sure your answer is in meters, not cm.

Opposite ends of the diameter are half that far apart.

Now just multiply that by 12.

Answer 2

R across A-B= R/2=(1/2)pie r rho=1/2(pie*10*0.1*12 = 0.6pie ohms.

Answer 3

Total resistance of wire = 12Ω×2π×10
−1

= 2.4π
Resistance of each half =
2
2.4π
​
=1.2π
and as about diameter both parts are in parallel
Req. =
2
1.2π
​
=0.6πΩ