Question

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

Answer 1

Real dip `theta=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 `theta` 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^@ #