Question

An electron moving with a velocity = 5.0 × 107 m/s enters a region of space where perpendicular electric and a magnetic fields are present. The electric field is = - 104 . What magnetic field will allow the electron to go through, undeflected?

Answer 1

Answer:

magnetic field will allow the electron to go through 2 x $10^{4}$  T k

Explanation:

Given data in question

velocity = 5.0 × $10^{7}$

electric filed = $10^{4}$

To find out

what magnetic field will allow the electron to go through, undeflected

solution

we know if electron move without deflection i.e. net force is zero on electron and we can say both electric and magnetic force equal in magnitude and opposite in directions

so we can also say

F(net) = Fe + Fb i.e. = 0

q V B +  q E = 0

q will be cancel out

$10^{4}j$ + 5e + 7i × B =  0

B = 2 x $10^{4}$  T k