A toroid having average diameter 2.5 m, number A turns 400 , current=2A and magnetic field has 10T what will be induced magnetic field (in amp/m)

Options

A. `(10^(5))/(4pi)`
B. `(10^(8))/(4pi)`
C. `(10^(8))/(2pi)`
D. `(10^(2))/(2pi)`

Answer

B

Explanation

`H=beta=mu_(0)(H+I)`
`10=mu_(0)((N)/(2pir)xxi+I)`
`I=(10)/(4pixx10^(-7))-(400x2xx2)/(2pixx2.5)=(10^(8))/(4pi)`