A current of 10 A flows, through a toroid having a core of means radius 25 cm. If 5000 turns of the conducting wire are wound on the core, then the magnetic field the core of thre toroid is

Options

A. `2 xx 10^(-2)Wb//m^(2)`
B. `3 xx 1-^(-2)Wb//m^(2)`
C. `4 xx 10^(-2)Wb//m^(2)`
D. `6 xx 10^(-2)Wb//m^(2)`

Answer

C

Explanation

`n=N/l=N/(2pir)=(5000)/(2pi xx 25 xx 10^(-2))=10^(4)/pi therefore B=mu_0nI=4pi xx 10^(-7)xx (10^(4))/pi xx 10=4 xx 10^(-2)Wb//m^(2)`