Surveying - Engineering

Q1:

The real image of an object formed by the objective, must lie

A in the plane of cross hairs

B at the centre of the telescope

C at the optical centre of the eye-piece

D anywhere inside the telescope.

ANS:A - in the plane of cross hairs

The real image is the plane of cross hairs because upper middle and lower number we have to get in this by cross hairs. The real image of an object formed by the objective must lie in the plane of crosshairs. If the image formed by the objective is not in the plane of crosshairs then the error is called as PARALLAX ERROR.