An electron moving with velocity 2 10⁻⁷ ~m / s , describes a circle in a magnetic field of strength 2 10⁻² ~T . If e m of electron is 1.76 10¹¹ C / kg . Then the diameter of the circle will be

Step-by-step solution

The force exerted on electron moving with velocity v is F=e v B where =90^ F_B=e v B ...(i) Centripetal force is given by F_C= m v^2 r ...(ii) Equating Eqs. (i) and (ii), we get r= m v^2 e B Diameter d=2 r= 2 v (e / m) B aligned d^ & = 2 2 10^7 1.76 10¹¹ 2 10⁻² & =1.1 ~cm aligned