Question

A dip needle arranged to move freely in the magnetic meridian dips by an angle θ. If the vertical plane in which the needle moves is rotated through an angle α to the magnetic meridian, then the needle will dip by an angle
in this quest why cosalpha <1 taken

Answer 1

Explanation:

A dip circle is so set that its needle moves freely in the magnetic meridian. In this position, the angle of dip is 40o. now the dip circle is rotated so that the plane in which the needle moves makes an angle of 30o with the magnetic meridian. In this position, the needle will dip by an angle.