Question

A solenoid of length `1*0m` and `3*0cm` diameter has five layers of windings of `850` turns each hand carries a current of 5 ampere. What is the magnetic field at the centre of the solenoid? Also calculate the magnetic flux for a cross-section of the solenoid at the centre of the solenoid.

Answer 1

Correct Answer - `2*671xx10^-2T`; `1*89xx10^-5Wb`
No. of turns, `N=850xx5`, Area of cross section,
`A=pir^2=22/7(3xx10^-2)m^2`, `l=lm`, `i=5A`.
Magnetic field induction at the centre of solenoid is
`B=mu_0Nil//l=4pixx10^-7xx(850xx5)xx5//1`
`=2*671xx10^-2T`
Magnetic flux `=BA`
`=2*671xx10^-2xx22/7xx(3/2xx10^-2)^2`
`=1*89xx10^-5Wb`