Vertically component of earth's magnetic field is BV=BHtanδ where, BH = horizontal component of earth's magnetic field δ=angle of dip Total intensity of earth's magnetic field B=BH6+BV2=BH2+BH2[∵tanδ=tan45∘=1]=2BH=1.44×0.4×10−4T=5.656×10−5T=0.5×10−4T