A long solenoid has 800 turns per meter length of solenoid. What is the magnatic induction at the end of the solenoid if it carries a current of 2.5 A?

Explanation

The magnetic B o the magnetic field along the solenoid.s central axis is related to the solenoid.s current `i` and number of turns per unit length n by Eq. 29-20 (`B=mu_(0)"in"`).
Calculation : Because B does not depend on the diameter of the windings, the value of n for five indentical layers is simply five times the value for each layer. Equation 29-20 then tells us
`B=mu_(0)"in"=(4pixx10^(-7)T*m//A)(5.57A)(5xx850"turns")/(1.23m)`
`=2.42xx10^(-2)T=24.2mT`.
To a good approximation , this is the field magnitude though out most of the solenoid.