Length of a solenoid is 50 cm and its total number of turns is 1250. if 2A current is a passed through it, what will be the magnetic field at any point on its axis ?

Explanation

Number of turns `1250`, lenghts `60 cm=0.6m`
`:.` Number of turns per unit length `n=(1250)/(0.6)m^(-1)`
So, the magnetic field at any point on its axis,
`B=mu_(0)nI`
`=4pixx10^(-7)xx(1250)/(0.6)xx2 [ mu_(0)=4pixx10^(-7)Wb*A^(-1)*m^(-1)]`
`=5.3xx10^(-3)Wb//m^(2)`.