If a magnet is suspended at an angle of 30o to the magnetic meridian, the dip needle makes an angle of 45o with the horizontal. The real dip is

Let the actual angle of dip (in the magnetic meridian) is θ. lf BH and, BV be the horizontal and vertical components of earth's magnetic field respectively, thentan⁡θ=BV/BHIn the plane situated at 30. with the magnetic meridian, see fig.(9) , the horizontal component of earth's magneticfield will be BH cos 30o while the vertical component will be BV. The angle of dip in this plane istan⁡45∘=BVBHcos⁡30∘∴tan⁡θtan⁡45∘=cos⁡30∘ or tan⁡θ1=32∴θ=tan−1⁡(3/2)