In night a plasma wind is blowing with a speed of 100 ms tow

In night, a plasma wind is blowing with a speed of 100 m/s towards the pole of the earth at an angle 70 deg with the magnetic line of force of the earth of strength 0.5 G. What is the strength of the electric field and its direction with respect to dawn or dusk?

Solution

v = 100 m/s

theta = 70 degree

B = 0.5 G = 0.00005 T

Now E = vBsin(theta) = 100*0.00005*sin70 = 0.0047 N/C = 4.7 mN/C