Question

At a place, the horizontal component of earth's magnetic field is B and angle of dip is 60°. What is the value of horizontal component of the earth's magnetic field at equator?

Answer 1

The horizontal component of the electric field is given by
BH=Becos(θ)
where θ is the angle of dip at the given place
Be is the net magnetic field

At θ=60°

BH=Becos(60)=Be×1/2

Be=2BH=2B (given BH=B)

Now horizontal component at equator

BH=B_ecos(θ)

angle of dip at equator is 0°

BH=B_ecos(0)=Be=2B

BH=2B