Answer:
The magnetic field is [tex]2 \times 10^{-4}[/tex] T
Explanation:
Given:
Velocity of electron [tex]v = 5 \times 10^{7} \frac{m}{s}[/tex]
Electric field [tex]E = 10^{4} \frac{V}{m}[/tex]
The force on electron in magnetic field is given by,
[tex]F = qvB \sin \theta[/tex] ......(1)
The force on electron in electric field is given by,
[tex]F = qE[/tex] ......(2)
Compare both equation,
[tex]qE = qvB \sin \theta[/tex]
Here [tex]\sin \theta = 1[/tex]
[tex]E = vB[/tex]
[tex]B= \frac{E}{v}[/tex]
[tex]B = \frac{10^{4} }{5 \times 10^{7} }[/tex]
[tex]B = 2 \times 10^{-4}[/tex] T
Therefore, the magnetic field is [tex]2 \times 10^{-4}[/tex] T
