Civil Engineering - Surveying - Discussion

Discussion Forum : Surveying - Section 2 (Q.No. 14)
14.
The desired sensitivity of a bubble tube with 2 mm divisions is 30". The radius of the bubble tube should be
13.75 m
3.44 m
1375 m
none of these.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
18 comments Page 1 of 2.

Rajni kant said:   1 decade ago
Sensitivity = [l*206265]/R.

R = ((2/1000)*206265)/30 = 13.75.
(1)

Chinna said:   1 decade ago
How to taken *206265 value?

Anshul said:   10 years ago
1 radian = 206, 265 seconds.

Sameer Kashmiri said:   9 years ago
If 30 = 2mm.

Then 1 =60" =4mm.

Then 1degree = 60 * 4 = 240mm.

It means 360 degree = 360 * 40 = 86400mm.
= 86.4 m.

R = L/2 * 3.14.
R = 86.4/2 * 3.14.
R = 13.75 m.

Rupayan Lahiri said:   9 years ago
@ Sameer Kashmiri.

There is a mistake in the third line of your comment. It will be 360 * 240 = 86400.

Pinku said:   9 years ago
2mm deflect with a small change of angle 30''
30'' ---> 2mm
60'' ---> 4mm
1' ---> 4mm.

For 360degree ---> 360 * 60 * 4.
So, 2 * 3.14 * r = 360 * 60 * 4.
r = 13.75.

Shailendrabsingh said:   9 years ago
Angle = arc/radius or =(d/r) radians.

Because 1 Radian = 206265 second.
So, = (d/r) * 206265 second.
Given that d = 2mm or 2 * 10^-3m.
So, ={(2 * -10^-3) * 206265}÷ r.
Then @ = 412.53÷r.
Given, 30second.

So r = 412.53÷30,
r = 13.75meter.
(1)

Roy said:   8 years ago
Thanks @Pinku.

MD FAISAL said:   8 years ago
In 30'----2mm.

So 360°=?
(360*60*60)'*2mm/30'=length of circumference.
So Lc=2*3.14*R.
(360*60*60)'*2/30'=2*3.14*R.
R=13.75m.
(2)

Tanmoy karmakar said:   7 years ago
30'' = 2mm,
1' = 4mm,
1° = 240mm,
360° = 240*360 = 86400mm,
2*π*r = 86400,
So, r = 13757.9mm = 13.75 m.
(8)


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