- #1

- 7

- 0

## Homework Statement

the filament of a 230V light bulb is 0.72M long and has a radius of 6.0 x 10^-2mm. The resistivity of the filamen metal is 1.2 x 10^-5 ohm metres. Work out the resistance of the bulb## Homework Equations

I have tried working out the area using pi x radius square but am having trouble converting 6.0x10^-2mm into metre square.i am using R=pL/A so i did 1.2x10^-5 x 0.72/1.1 x 10^-8m^2 which equals 785 ohms but the answer is 760 ohms can anyone please help me out?