An electron gun is placed inside a long solenoid of radius R on its axis. The solenoid has n turns/length and carries a current I . The electron gun shoots an electron along the radius of the solenoid

Question

An electron gun is placed inside a long solenoid of radius $R$ on its axis. The solenoid has $n$ turns/length and carries a current $I .$ The electron gun shoots an electron along the radius of the solenoid with speed $v .$ If the electron does not hit the surface of the solenoid, maximum possible value of $v$ is (all symbols have their standard meaning):

TestHub · Accepted Answer

Magnetic Field Inside Solenoid is B = μ 0 n I Velocity ν has given to the electron So, Magnetic Force F = q ν B as ν and B are perpendicular. In a magnetic field, charge will move on a circular path. Here, If radius is just less than or equal to radius of solenoid then the electron does not hit the surface. F = q ν B = m ν 2 R ⇒ m ν = q B R a s q = e ν = e B R m S o , V = e μ 0 n I R m

Physics - Magnetism Question with Solution | TestHub

Options:

Doubts & Discussion