A long solenoid has `200` turns per cm and carries a current `i`. The magnetic field at its centre is `6.28xx10^(-2)` `weber//cm^(2)`. Another long solenoid has `100` turns per cm and it carries a current `(i)/(3)`. The value of the magnetic field at its center is

Options

A. `1.05xx10^(-2)"Weber/m"^2`
B. `1.05xx10^(-5)"Weber/m"^2`
C. `1.05xx10^(-3)"Weber/m"^2`
D. `1.05xx10^(-4)"Weber/m"^2`

Answer

A

Explanation

`B_2/B_1=(mu_0n_2i_2)/(n_0n_1i_1)
impliesB_2/(6.28xx10^(-12))=(100xxi/3)/(200xxi)`
`impliesB_2=(6.28xx10^(-2))/6=1.05xx10^(-2)Wb//m^2`