Problem
Calculate the radius of the circular path taken by an electron moving at \( 5 \times 10^5 \, \text{m/s} \) in a magnetic field of \( 0.4 \, \text{T} \). (Given: charge of electron \( = 1.6 \times 10^{-19} \, \text{C} \), mass of electron \( = 9.11 \times 10^{-31} \, \text{kg} \))