Question

An electron moving with a velocity = 5.0 × 10 7 m/s enters a region of space where perpendicular electric and a magnetic fields are present. The electric field is = . What magnetic field will allow the electron to go through the region without being deflected?

Answer 1

The magnetic field is
`2 * 10^(-4)` T

Step-by-step explanation:

Given:

Velocity of electron
`v = 5 * 10^(7) (m)/(s)`

Electric field
`E = 10^(4) (V)/(m)`

The force on electron in magnetic field is given by,

`F = qvB \sin \theta` ......(1)

The force on electron in electric field is given by,

`F = qE` ......(2)

Compare both equation,

`qE = qvB \sin \theta`

Here
`\sin \theta = 1`

`E = vB`

`B= (E)/(v)`

`B = (10^(4) )/(5 * 10^(7) )`

`B = 2 * 10^(-4)` T

Therefore, the magnetic field is
`2 * 10^(-4)` T