A narrow electron beam passes undeviated through an electric field E = 3 `xx` 104 V/m and an overlapping magnetic field B = 2 `xx` 10-3 Wb/m2 . The electron motion, electric field and magnetic field are mutually perpendicular. The speed of the electron is
When u equate the electric force and the magnetic force u get the velocity, v=E/B
therefore,given,E=3 x 10^4 & B=2 x 10^-3
v= 3 x 10^4/2 x 10^-3=1.5 x 10^7 m/s
Therefore,the answer is option 2.