If earth is considered as a short magnet with its centre coinciding with the centre of earth. Then the angle of  dip 𝛅 at a place where the magnetic latitude ‘ λ’ given by

For  Msinλ, point P is  axial point Hence  B1=μ04π2MsinλR3For  Mcosλ point P is equatorial point        B2=μ04πMcosλR3Here  B1,B2  represents  BV,BH at the point ‘P’Dip at the point ‘P’tanδ=BVB  H =B1B2=2tanλ ⇒tanδ=2tanλHence key (1) is correct.