Question

An electron moves through a region of crossed electric and magnetic fields. The electric field E = 3059 V/m and is directed straight down. The magnetic field B = 1.14 T and is directed to the left. For what velocity v of the electron into the paper will the electric force exactly cancel the magnetic force?

Answer 1

Answer:

v = 2683.33 m/s

Explanation:

The magnetic force and the electric force on the electron must be the same, in order for them to cancel each other:

$Electric\ Force = Magnetic\ Force\\Eq = qvBSin\theta \\\\v = \frac{E}{BSin\theta}$

where,

v = velcoity of electron = ?

E = Electric Field = 3059 V/m

B = Magnetic Field = 1.14 T

θ = Angle between velocity and magnetic field = 90°

Therefore,

$v = \frac{3059\ V/m}{(1.14\ T)Sin90^o}$

v = 2683.33 m/s