A narrow electron beam passes undeviated through an electric field E = 3 × 104 v/m and an overlapping magnetic field B = 2 × 10-3 wb/m2. The electron motion, electric field and magnetic field are mutually perpendicular. The speed of the electron is _______.
A. 60 m/s
B. 10.3 × 107 m/s
C. 1.5 × 107 m/s
D. 0.67 × 10-7 m/s
Answer:C
A narrow electron beam passes undeviated through an electric field E = 3 × 104 v/m and an overlapping magnetic field B = 2 × 10-3 wb/m2. The electron motion, electric field and magnetic field are mutually perpendicular. The speed of the electron is _______.
A. 60 m/s B. 10.3 × 107 m/s C. 1.5 × 107 m/s D. 0.67 × 10-7 m/s