If a magnet is suspended at an angle of 30^o30o to the earth magnetic meridian , the dip needle makes angle of 45^o45o with the horizontal . the real dip is ?

1 Answer
Apr 16, 2017

Real dip theta=40.9^@θ=40.9

Explanation:

Let the vertical component of earth's magnetic field be V and its horizontal component at magnetic meridian be H.

Then the angle of dip thetaθ at magnetic meridian will be given by

tantheta=V/H......[1]

When the dip needle is suspended at an angle of 30^@ to the earth magnetic meridian then it makes an angle 45^@ with the horizontal.

In this situation vertical component of earth's field responsible for its orientation with the horizontal direction, remains same as V but the component in horizontal direction becomes Hcos30^@

So tan45^@=V/(Hcos30^@)

=>V/H=cos30^@.......[2]

Comparing [1] and [2] we get

tantheta=cos30^@=sqrt3/2

=>theta=tan^-1(sqrt3/2)~~40.9^@