A tightly- wound , long solenoid carries a current of 2.00 A. An electron is found to execute a uniform circular motion inside the solenoid with a frequency of `(1.00 xx 10^8 rev s^-1`). Find the number of turns per metre in the solenoid.

Explanation

Given current`
` `I = 2A`
` frequency `f=1xx10^8rev // sec`
`m = 9.1xx10^(-31)`kg,
`q=1.6xx10^(-19) C`
We know that `B = mu_(0)ni`
Since `f = (qB)/(2pim) rArr B = (2pimf)/(q)`
`rArr mu_(0)ni = (2pimf)/(q) [using (1)] `
`n=(2pimf)/(mu_(0)qi)`
`=(2pixx9.1xx10^(-31)xx1xx10^8)/(4pixx10^(-7)xx1.6xx10^(-19)xx2)`
=1420A.