Civil Engineering - Surveying - Discussion

Discussion Forum : Surveying - Section 4 (Q.No. 5)
Which of the following introduces an error of about 1 in 1000 if 20 m chain is used
length of chain 20 mm wrong
one end of the chain 0.9 m off the line
one end of chain 0.9 m higher than the other
middle of the chain 0.45 m off the line
all the above.
Answer: Option
No answer description is available. Let's discuss.
12 comments Page 1 of 2.

Shah Sawar said:   3 years ago
Slope Correction or error = h^2/2L.

Now we want to find the difference in height of chain ends for which 1 in 1000 or 20 mm in 20 m chain length will produce.

0.02 = h^2/(2 x 20),
h = 0.9 m,
So, option B along with A, C options is correct.

Maithri said:   4 years ago
Can you explain how you got 0.89 @Sudip.

NAMAN soni said:   4 years ago
Please explain the given solution.

Sudip said:   4 years ago
Slope error= 20mm = h^2/2L.
Then, h=0.89m~0.9m.
i.e. one end is 0.9m higher/lower than another end.

Raz said:   4 years ago
Why all of the above.

Laxmi said:   4 years ago
Please give an explanation clearly.

Biks said:   6 years ago
Answer should be A.

Saikat said:   6 years ago
1 in 1000 means 1000 m = 1m.
then 20 m = 1/1000* 20=20mm.

Ritu said:   6 years ago
Someone please explain the concept.

Ramakanth said:   7 years ago
Explain the answer.

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