Two concave lenses of 60 cm focal length are cemented on either side of a convex lens of 15 cm focal length. The focal length of the combination is_____.

Civil Engineering : Surveying - Quiz(MCQ)

10 cm

20 cm

30 cm

40 cm

Correct Answer : 30 cm

Recently Updated in Surveying Questions

A sewer is laid from a manhole A to a manhole B, 250 m away along a gradient of 1 in 125. If the reduced level of the invert at A is 205.75 m and the height of the boning rod is 3 m, the reduced level of the sight rail at B, is_______.

202.75 m

206.75 m

208.75 m

211.75 m

Correct Answer : Option (B) : 206.75 m

In a closed traverse, sum of south latitudes exceeds the sum of north latitudes and the sum of east departures exceeds the sum of west departures, then, the closing line will lie in

north east quadrant

north-west quadrant

south-west quadrant

south-east quadrant

Correct Answer : Option (B) : north-west quadrant

The Huygen's telescope eye piece________.

achromatic

is aplanatic

Both (A) and (B)

Neither (A) nor (B)

Correct Answer : Option (C) : Both (A) and (B)