Given that
The number of turns per unit length is n = N/L
                                                          Â
= 110turns /cm
                                                         Â
= 11000 turns /m
Radius is R = 2.54 cm
                  Â
= 2.54*10^-2 m
Speedof electron is v = 0.0635c
                                   =
0.0635*(2.998*10^8m/s)
                                   =
0.1903*108m/s     Â
-----------------------------------------------------------------------------------------------------
    If the electron moving in uniform
magnetic field then
                                      Bev
= mv2 /R
                                          B
= mv / R*e
                                      Â
= (9.11*10^-31 kg)(0.1903*10^8 m/s ) /(2.54*10^-2
m)(1.602*10^-19C)Â Â
                                              =
0.426 *10^-2 T
    The magneticfield inside the solenoid is
B = μ0*n*I
                                                                    I=
B / μo*n    Â
                                                              Â
= 0.426 *10^-2 T / (4Ï€*10^-7 T.m /A * 11000 turns/m )
                                                                    =3.08
A
I hope help you.