Anelectric field of 1.7 KV/m and a magnetic field of 0.422 T act on amoving electron to produce no net force. If the fields areperpendicular to each other, what is the electron speed? Give theanswer in km/s and to three significant figures.
2. Q.28-2
Anelectric field of 1.7 KV/m and a magnetic field of 0.422 T act on amoving electron to produce no net force. If the fields areperpendicular to each other, what is the electron speed? Give theanswer in km/s and to three significant figures.
Explanation / Answer
Given : Electric field ( E) = 1.7 kV /m = 1.7 x 103 V /m Magnetic field ( B) = 0.422 T Lorentz Force is : F = B q v + E q The electron is moving such that the net force F = 0 0 = B qv + E q or B q v = - E q or v = - E /B = -(1.7 x 103 V/m) / 0.422 T = - 4.028 x 103 m /s Here -ve sign represents the direction . Hence velocity of electron is : v = 4.028 x 103 m /s Hope this helps u!