Which of the following is/are correct statement$\text{(s)}$?
- Back Bearing of a line is equal to Fore Bearing $\pm 180^{\circ}$
- If the whole circle bearing of a line is $270^{\circ}$, its reduced bearing is $90^{\circ} \text{NW}$
- The boundary of water of a calm water pond will represent contour line
- In the case of fixed hair stadia tachometry, the staff intercept will be larger, when the staff is held nearer to the observation point