An electron is shot into one end of a solenoid.As it enters the uniform magnetic field within the solenoid its speed is 800m/s and its velocity vector makes an angle of `30^@` with the central axis of the solenoid. The solenoid carries 4.0 A current and has 8000 turne along its length. Find number of revolution made by the electron within the solenoid the time emerges from the solenoid's opposite end. (Use charge to mass ration e/m for electron `sqrt3 xx10^(11) C/kg)` Fill your answer of y if total number of revolution is `y/5 xx10^8`

Answer

8