Q. In the experiment for the determination of $ \frac{e}{m} $ of electrons by the Thomson method, electric and magnetic fields are
J & K CETJ & K CET 2003
Solution:
In Thomson's .experiment to determine the charge to mass ratio of an electron, his apparatus was as follows:
A uniform magnetic field is created between $X $ and $Y$, by applying a potential difference between them. In the same region and outside the tube is placed an electromagnet which produces a magnetic field perpendicular to the plane of paper. Thus, two fields are produced in the same region perpendicular to each other, also the two fields are perpendicular to the motion of electron.
