A long solenoid has 20 turns per cm and carries a current i. the magnetic field at its centre is `6.28xx10^(-2)Wb//m^(2)`. Another long solenoid has 100 turns per cm and it carries a current `i//3` . The value of the magnetic field at its centre is

Options

A. `1.05xx10^(-4)Wb//m^(2)`
B. `1.05xx10^(-2)Wb//m^(2)`
C. `1.-5xx10^(-5)Wb//m^(2)`
D. `1.05xx10^(-6)Wb//m^(2)`

Answer

B

Explanation

`B=mu_(0)ni`