The true value of angle of dip at a place is 60º the apparent dip in a plane inclined at an angle of 30 ºwith magnetic meridian is

 A magnetic meridian is defined as a line on the earth’s surface approximating a great circle, which passes through the north and the south magnetic poles.

Solution

We know that tanψ=tanϕ/cosβ

where

ψ= apparent angle of dip,

ϕ = true angle of dip 

β = angle formed by vertical plane with magnetic meridian 

tanψ = [(tan60°)/(cos30°)]

= [√3/(√3/2)] = 2

 ψ = tan–1(2)