Engineering :: Surveying

@ : Home > Civil Engineering > Surveying

61.

A French cross-staff has a magnetic compass at the top.

Right

Wrong

62.

An open cross-staff is commonly used for setting out

A.	short offsets	B.	long offsets
C.	oblique offsets	D.	none of these

63.

An optical square is used for the same purpose as the cross-staff, but it is more accurate.

Yes

64.

The angle of intersection of the horizon glass and index glass in an optical square is

A.	30?	B.	45?
C.	60?	D.	75?

65.

The horizon glass in an optical square is

A.	wholly silvered	B.	wholly unsilvered
C.	one-fourth silvered and three-fourth unsilvered	D.	half silvered and half unsilvered

66.

The index glass in an optical square is

A.	wholly silvered	B.	wholly unsilvered
C.	one-fourth silvered and three-fourth unsilvered	D.	half silvered and half unsilvered

67.

The optical square is used to measure angles by

A.	refraction	B.	reflection
C.	double refraction	D.	double reflection

68.

The instrument, belonging to a class of reflecting instrument, is

A.	line ranger	B.	box sextent
C.	prismatic compass	D.	all of these

69.

In an optical square, the angle between the first incident ray and the last reflected ray is

A.	60?	B.	90?
C.	120?	D.	150?

70.

When the object lies on the left hand side of the chain line, then while taking offset with an optical square, it is held in

A.	left hand upside down	B.	right hand upside down
C.	left hand upright	D.	right hand upright