# Civil Engineering - Surveying - Discussion

Discussion Forum : Surveying - Section 1 (Q.No. 28)
28.
Pick up the correct statement from the following:
the theodolite in which telescope can be rotated in vertical plane is called a transit
when the vertical circle is to the left of the telescope during observation, it is called to be in left face
when the vertical circle is to the right of the telescope during observation, it is called to be in right face
all the above.
Explanation:
No answer description is available. Let's discuss.
Discussion:
7 comments Page 1 of 1.

Bittu said:   2 years ago

Siddhi mahtre said:   3 years ago
Nice. Thanks all.

Excellent explanation@ Thanks Neeraj.

Chitra said:   5 years ago
Thanks @Neeraj.

Paras maskare said:   6 years ago
Thanks @Neeraj.

Shubham said:   6 years ago
Good explanation, Thanks @Neeraj.

Neeraj said:   6 years ago
Transiting:

It is also known as plunging or reversing. It is the process of turning the telescope about its horizontal axis thought 180° in the vertical plane thus bringing it upside down and making it point exactly in opposite direction.

Swinging the Telescope:

It means turning the telescope about its vertical axis in the horizontal plane. A swing is called right or left according as the telescope is rotated clockwise or counterclockwise.

Face Left:

If the vertical circle of the instrument is on the left of the observer while taking a reading, the position is called the face left and the observation taken on the horizontal or the vertical circle in this position is known as the face left observation.

Face Right:

If the vertical circle of the instrument is on the right of the observer while taking a reading, the position is called the face light, and the observation taken on the horizontal or the vertical circle in this position is known as the face right observation.

Changing Face:

It is the operation of bringing the vertical circle to the right of the observer if originally it is to the left, and vice- versa. It is done in two steps: firstly revolve the telescope through 180° in a vertical plane and then rotate it through 180° in the horizontal plane i.e. first transit the telescope and then swing it through 180°.
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