If ₁ and ₂ be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of dip is given by

Step-by-step solution

Let the B_H and B_V be the horizontal and vertical component of the earth's magnetic field B . Let plane- 1 and 2 be mutually perpendicular planes making angle and (90^ - ) with magnetic meridian. The vertical component of the earth's magnetic field remain same in two plane but effective horizontal components in the two planes is given by Then, ₁= B_V B₁ = B_V B_H Similarly, ₂= B_V B₂ = B_V B_H From Eqs. (iv) and (v), we get aligned & ^2 ₁+ ^2 ₂ & = B_H^2 ^2 B_V^2 + B_H^2 ^2 B_V^2 & ^2 ₁+ ^2 ₂= B_H^2 B_V^2 ( ^2 + ^