The plane of dip circle is set in the geographic meridian and the apparent dip is `theta_(1)`. It is then set in a vertical plane perpendicular to the geographic meridian. Now, the apparent dip is `theta_(2)`. The angle of declination `theta` at that place is

Options

A. `theta=tan^(-1)(tan delta_(1) tan delta_(2))`
B. `theta=tan^(-1)(tan delta_(1)+tan delta_(2))`
C. `theta=tan^(-1)(tan delta_(1)/tan delta_(2))`
D. `theta=tan^(-1)(tan delta_(1)-tan delta_(2))`

Answer

C

Explanation

`Here, tandelta_(1)=(V)/(Hcostheta)`

`tan delta_(2)=(V)/(H cos (90^(@)-theta))=(V)/(H sin theta)`
`tan delta_(2)/(tan delta_(2))=(sin theta)/(sin theta)=tan theta`
`theta=tan^(-1)((tan delta_(1))/(tan delta_(2)))`